I just finished playing V188.8.131.52 released by GOG several months ago. I believe it reflects some of the changes we can expect in the final version. The version wasn't free of graphic bugs involving lightings, but the pace was smooth and some of the dialogue has be streamlined. I didn't feel I missed anything from the previous version.
For more noticeable changes: the rendering for Storytime was with exceptionally soft focus, beginning with the point of focus and increasing with more distant objects. I had "Depth of Field" turned off. I assume it was to enhance the dream-like atmosphere. The soft focus continued into Friars' Keep with the Point of focus sharp, but the back ground soft. Daytime Propast in Book 1 was literally night with bright lights everywhere. The experience was "neon lights and darkness". Light bots were everywhere.
I wasn't able to arrange a meeting between Ada and Sully. I think that that optional dialogue between Zoe and Sully has been eliminated.