Hello fellas. As many have pointed out, with the new update the game feels somewhat slower and has some irritating problems with the UI, engine and overall gameplay (for me personally, i couldn't quicksave and would get random error screens in The Beyond sometimes, not to mention how laggy combat is) and these problems can really drag down the gameplay experience. And while i have faith in Tjop to work on fixing these problems in near future, i DO have some temporary solutions that might help in the moment:
First of all, obviously, the way to counteract the quicksave problem, is to just save manually or use autosaves. When an error screen pops out, press "Rollback", then proceed to save in the proper slots.
As for the overall jagginess: i found that the problem stems from the game being poorly optimized in some areas. it is unclear how this could happen, as renpy is usually not an engine that is very heavy on the system, unless it's employing constant complex animations, which is hard to say if that would be the case here. But it is a notoriously unstable one, so i would not necessarily blame the developer for this.
Anyways, the "Bandaid" solution to it is to simply: close any applications that may drain your computer's processing, then
(this is the important part)
open taskbar => navigate to the big beyond(while it's open) => go to details => set priority => then choose "high" or "realtime", depending on your setup.
this should help in the short-term, while the root cause is being worked on. Good luck, and enjoy the game!