The I.D. will use a different layout/grid set for each level after the first. ...

The I.D. will use a different layout/grid set for each level after the first.  The probabilities now use a normal distribution to, statistically, rotate through all possibilities as depth increases.

The size of each I.D. level will gradually increase with depth, and random layout parameters, including number of enemies and other parameters, are adjusted in order to maintain approximately equal difficulty across different layouts.

Some more layouts can have random rooms.

Updated some NicerTiles parameters for some grids and fixed a bug with the treasure1 vault that could cause its entrances to be blocked.

The I.D. will generate two exits per level (extra one separated from the start and the normal exit), each leading to a different layout/grid scheme, which will be reflected in the tile used for the exit.
Stair guards (for both exits) are now generated randomly, making their presence more unpredictable (and slightly more common).  The probability is a periodic function of depth (levels 5+, automatic at level 30+).

The I.D. challenge quests have been adjusted:
Quest text has been expanded and clarified in a few places.
The challenge award probabilities for a prodigy (more than 1 is very rare) or a category point (tends towards 1 per 30 character levels) have been adjusted based on how many have already been awarded and the number of character levels the player has gained in the I.D.