Thanks for the update. Just sent my save to them. The instructions to get your save are here:
https://larian.com/support/faqs/retrieving-requested-files_81 under "Saved Games". Remember, it should be a .lsv file. I had to ask my host to follow the instructions and send me their save, for me to send to Larian. Please do so while the the iron's hot and they're taking an active interest in this issue
EDIT: Here is the reddit thread for anyone interested, where you can also see the Sr. Community Strategist's response:
https://www.reddit.com/r/BaldursGate3/comments/18ch2tu/act_3_multiplayer_tposing_crashing/
