Well hard to predict but here are my observations (based on becoming regular since about Fall 24 [i.e. about a year] - prior to Fall 24 game was way too buggy and merited its low scores. Since about Nov24 it's been playable in my view)
- Current stability: about the best it's ever been and I think fine. Since Sep Steam haven't been having crashes, saves seem generally stable - things like Dragon are now consistently usable it seems. Some weirdo items as noted, like in some circumstances Trolls, Ogres becoming floating eyes, and for some armor meshes your legs going invisible during sex....
- Progress & Carryforward:I have two parallel saves I am using depending on my mood. One is a Steam Clean Start from August (after warning from Dev that prior wouldn't per se work) and one from 8.6.1 (so if I am not getting that wrong, Dec 24ish, pre-Steam, from here). For 8.6.1 in fact it continues to work well - I did have to reconstitue via cheat menu my equipment when coming into Steam version, but I knew that, had made note of what I wanted to "cheat-restore" and did so via the cheat menu no pain. so I have one ongoing that is all the way back to end 24 / early 25 (the save version prior to that however didn't work, so prior to 8.6.1 seemed buggered)
- This build update partially wiped out buildings (and anything in non-food storage chests. As there is now a Free Build option in cheat, can restore wiped out (price to pay for the improved buildings, after using now while at first I saw no difference, I can say there's at least marginal improvement and at minimum for Wood and some Stone the models are more visually attractive, plus sizing seems more standardised so that things snap-fit better as noted here above - better is not perfect but still better. and the add-in stuff to decorate up one's abode is cool.
- Although at first I was irritated to have to rebuild my lair for my 8.6.1 origin save, in fact now I am kind of pleased as original build under old 8.6.1 was messy, I have cleaned up. No big meaning to that but if you like the lair building it's fun
- Character: so far for all-presets I did from 8.6.1 on everything has imported fine and ongoing saves no skills or similar wiped out / reset. I saw some people indicate tattooes screwed up but did not myself experience (and easy enough to redo on edit of the preset). The update pre-steam ( I think Sep/Oct? 24, forget now) what completely wiped character progress seems to be a think of the past.
So overall - and extent now to which the Dev seems to personally be very invested in the idea of Steam Success, seems like a reasonable moment - upgrades don't seem to any more utterly wipe out character progress and loot or equipment items the cheat-system allows you to restore easily
If I recall correctly now (From Steam versions on) one has to place the Required Items in the Loot section, that it doesn't pull from inventory.
There is inconsistency between crafting stations, some pull from inventory, some do not. Hopefully in future a Quality of Life upgrade will be done to make them all work in the same way just to avoid confusion / forgetting one works from inventory, another doesn't....
Last updates I suspect were for Steam environment saving
(as I am in Steam itself thanks to having thrown subscription $$ Jan-July [after 8.6 series convinced me worth it) - as initially I was seeing crashes on saving (saving sometimes triggered a crash and exit which would sometimes wipe out built items) and that's gone away - plus save speed is now much faster and consistent. I think time period of this aligns with those hotfixes.