Fellow Dwarves, after a late night and early morning, we have found the issue to the autosave problem and put in a fix.
Auto saves are about a 10th of a second on new games, with all the of the various cut outs that get done into the voxel world by the new poi system in the advanced caves and thus have been reactivated.
We've also changed the prompt on the exit game (to citadel and to desktop) asking if you want to save, which will bring up the save game screen.
Thank you for your patience, and we are continuing on with work on the next patch, but more details to be released later.