I have reduced them somewhat. Since it's only happening in the wilderness I do not see too much of a problem.

And BTW, it's a hint dependent on your corruption level and moves spent in order to draw you towards the caverns of Chaos. The pull of the gate...

Oh, it points to the CoC all the time? I thought it was pointing to the nearest extra dungeon. I must be really bad at reading directions then :D
Well, a single trip from Darkforge to DDL to clear doom nets about 6-7 messages with ~40k turns in-game and 1 corruption. I don't know whether this was intended or a 1000x corruption point modifier bug (which causes negative score) has an impact but it was too much for me.

Anyway, thanks for reducing this.

Yes, I've noticed it points specifically to CoC but the problem is that at the stage of the game when it starts appearing, I still have a lot of wilderness traveling to do and it's very annoying.
I don't have any corruptions either.
When it stacks with weather effects and stuff like amulets of order changing N chars' alignment then it's a guaranteed (more) prompt every 1-2 turns.
I think it should start no sooner than day 40-50 of in-game time or at 40k turncount mark.

You don't have any corruptions, but you still are severely tainted by chaos, because of that corruption bug LN mentioned. You know, like lvl6 PC dies, gets massive negative score because he was severely tainted by chaos. So in next release its probably going to start a lot later :)