This may not be a particularly important idea due to the similar nature of control teleport, but I think an amulet that stops all PC teleportation (rather than letting you control it) would be a good addition. It is not very hard to get teleportitis, but much more difficult to remove it.

Of course, the main uses for this would be spellbooks (without having to go to certain areas) and removing tedium from the casino, as well as completely remove the risk of accidentally robbing shops (perhaps you misclick and cancel the controlled teleport, causing you to randomly TP).

It has the downside of accidentally having it on and wasting a TP charge, or putting on a cursed one and being stuck with it for some time. I think it could even autocurse like Ring of the Fish. Additionally, maybe the teleportitis restriction on smithing could be removed (forcing you to have an amulet of stasis if you want to smith).

Stasis could also be assigned to some new artifacts, which could act as an extremely significant downside to using one... or perhaps not an issue at all, for some characters.