I don't see any harm in adding this. In fact, I don't see any harm in allowing intrinsic invisibility or elemental imunities to be wished for. Invisibility is powerful, yes, but it is available from pools, so I don't see the problem with allowing it to be wishable. Immunities, on the other hand, aren't as powerful as people sometimes make them out to be. They're nice, but far from essential. There are a vanishingly small number of instances where directly wishing for an elemental immunity would be stronger than wishing for a ring of elemental mastery or a colour dragon scale mail, so why not?

Is there a chance this still gets implemented? I just had a game where I got teleportitis and it was a NIGHTMARE.
I had two wishes, I'd gladly have used both of them to get rid of this damn intrinsic, but I couldn't.
If getting rid of it (or getting it for some sick reason) was wishable it would certainly be a nice addition.
Immunities would definitely be too much (since they are active without any items vs rings or armors you have to wear) so I'd opt only for the things that you can normally get by pool sipping - resistances and other specials.

Can one not wish for an item of teleport control?

"Amulets of teleport control". There you go.

If your complaint is about teleportitis itself instead of the lack of control,

a) even in the most pessimistic evaluation controlled teleportitis doesn't qualify as a NIGHTMARE,
b) you either inflicted it on yourself by drinking from pools or eating a pixie, in which case hopefully you've learnt your lesson.

Got it from drinking a pool and I had intrinsic tele ctrl anyway, plus additional ring plus another blink dog corpse stashed in a shop.
That's beside the point, reading books or farming herbs is extremely tedious with it, occasionally moving around is interrupted by -tpis kicking in, while the cursor is at the wall and you get teleported randomly.
It kicks in while fighting tough/difficult monsters and carefully reading every message. In this case you have to abort it or choose a destination and read through two lines of useless text.
This is a subjective opinion and I repeat this: controlled or not, teleportitis is a nightmare, especially when I already have teleport on demand (that's the case most of the time anyway) via wand or a spell.
Perhaps I was misunderstood. I never pool-sip without external means of teleport control, namely the ring. Non-controlled tpis is of course much worse than controlled one.

The idea was that with wishable pool instrinsics, you could either wish for "teleporting" which would grant you the intrinsic or "steadiness" which would take it away.

If it's that much of a nightmare to you, don't drink from pools. It's really as simple as that.

Sometimes the pool is the only source of wishes when you have not found a wand or a ring, and intrinsics when there are no corpses, and I'm willing to take that risk to obtain those.
I would simply like to have even an expensive option to remove certain "powers" because there is no other way to do so without drinking from a pool again and hoping for the best.
Even the greatly undesirable dooming and cursing can be rather easily removed by sacrificing on an altar. Why not other things?
I'm really not asking for a lot, only to include the option to get rid of certain things via wishing. A wish like that isn't really game breaking and there are much more useful wishes if teleportitis doesn't not annoy you as much as it does me.
Alternatively there could be a ring of steadiness, that entirely prevents spontaneous teleportation either via intrinsic or traps. That would be amazing.

EDIT: I forgot to add: Teleportitis can be absolutely deadly in darkforge.

You said it yourself, it's a RISK, sometimes when you gamble you lose. Pools are not intended to be all upside.

That said I'd like to see a way to lose teleportitis or a way to prevent it from interrupting actions like reading and digging.

There already is. Do your reading in a level that prevents teleportation, like the water temple. As for digging with pickaxes, it only impedes it somewhat; I've never had trouble doing the digging I needed to do while I had teleportitis. (Not to mention that if the level you're currently on allows teleportation, you can just teleport. Why are you digging in the first place?)

While we're at it, with the exception of Wish you can read pretty much any spellbook in the game without being teleported if you try often enough, and you can do that in a non-corrupting area like the wilderness. All it takes is game time.

I guess if you enter the new Darkforge with teleportitis somehow (from drinking the two, three pools you've found up till that point) you could be in for a nasty surprise - but nothing, as far as I can tell, that would have to be immediately fatal, or that couldn't be fixed by more teleporting (wands and such). Unless your PC is going to get one-shotted by steel golems, in which case teleportitis or no they had no business being in Darkforge in the first place. If teleportitis turns out to be absolutely deadly in Darkforge, that's 90% on Darkforge and 10% on the actual teleportitis. Keeping in mind that teleportitis is a self-inflicted condition, I am mystified why I should care. Darkforge is dangerous. Good!

"It wouldn't be game-breaking" as an argument resembles the Chewbacca Defense. No one suggested it was.

And mentioning dooming and cursing in this context is just shooting yourself in the foot. You know what you can't wish for either? The removal of dooming or cursing. There are plenty of other nasty things that wishes can't cure. That's what helps make wishes interesting. They need some limitations. That they can't grant intrinsics is a very easy to grasp and elegant one that needs no fixing whatsoever.

Nothing important, but as Silfir said if you use Dark Forge being deadly as a reason, you are really stupid going there with a character that can die to the golems. I always get teleportitis as soon as I can after getting control and I always go to Dark Forge with said intrinsic and I have never lost a character there in 1.2.0.

If you don't like teleportitis then just don't get it. Wishes are not that important. There is more than enough other means of acquiring items, intrinsics and what not. If you are a spellcaster you need wishes even less.

Anyway, this RFE has been upvoted a long time ago, I even supported it. Why are we here again?

We are here again because there is no response to it from someone who could actually implement it.
As for reading books in places that don't allow teleportation - what if you don't have the access to any such places right away? I know I can still read spellbooks when teleporting, I was successful many times and it can be lived with, it's just annoying, especially when you already have ~10 scrolls of chaos resistance, plenty of holy water, 7LB, GoGS, AoLS, dragon plate mail and a spare wand of wishing (2). You can't be sure what to use the wishes for, I'd use them to remove teleportitis but there is no such option.
Am I asking for that much? Just make it toggleable via wishing, that's it.

As for digging, I had a game where an altar was generated in D:2 in a corner but the level layout pretty much prevented monsters from wandering in to be sacced. So I decided to dig out connecting tunnels and make a swiss cheese out of the level. Teleportitis prevents that or at least makes it painful and annoying.

Going into darkforge with a character that can handle one golem with some difficulties but can't handle 2 or more at once is quite typical. You use choke points to let them come to you one by one and escape upstairs to regenerate.
If you get randomly teleported to the corridor with many golems, you will be killed.
I had a situation where I could not even use my wand of teleportation to randomly teleport again because it burned the very same turn I was randomly teleported next to four golems and one of them used fire attack on me.
If I didn't have teleportitis, I'd have survived. Of course it did not kick in again, not in time to teleport me safely away and I died.
Sometimes you're going through a dungeon, you heap of four large rations was destroyed by an undiscovered acid trap, you are starving, no monsters around.
Then, a pixie teleports next to you, you kill it and it drops a corpse. If you don't it eat, you will starve to death. If you do, you get telepotitis.
As for being unable to wish for removal of dooming and cursing, you can still wish for enough gold to sacrifice and get those intrinsics removed. Same for getting luck and fate - sac gold that you wished for and voila. Indirect but possible.
The same cannot be said about teleportitis. You can mitigate it with teleport control but not remove it entirely.

... And?

None of that actually supports your argument. You're just recounting typical ADOM stories.

I see room for improvement here, that's it. No extra help for the player, just more options and possibilities, that can't hurt.

I see you made the priority 'lowest', that means it will be something looked into last. Not any earlier, together with other lowest priority RFEs. We all have been playing ADOM with teleportitis for many years. Because you don't like it, now all of a sudden it must be looked into immediately. We all are waiting for improvements. There are things much more important than looking into one or two players' dislikes.

There has not been significant development on RFEs since pre9. There are still several major bugs that were introduced in pre9ish that haven't been fixed yet.

Be patient. There are upwards of 300 RFEs that have not been addressed by the Creator.

Fine, I rest my case. There are many RFE more important than this.

Any chance to still get this looked into?

I've not seen this before. Why not? It adds flexibility to gameplay, it's presents an extra choice when pondering what to wish for (which in my mind, and as Blasphemous has already said, makes for a tough decision what with all the other first-choice wishes), and with wish engines out of the game it's not abusable.

-Petr, -Para, and -Deth being obtainable by wishes seems like a pretty cool idea with me. It would definitely enhance artifact flexibility. I'm not going to get involved in the -Tele debate lol.