So I was having the Act 2 issue where I couldn't save or well do anything. It affected every save, so it wasn't a corrupted save as I first thought. One thing I did to "fix" the issue was to close out of steam completely, not have it running at all, and then launch it directly from the exe. I ran almost a full half hour without a crash, then I ran out of memory with the error below. Maybe I just need to bump up my PC to 1 TB of RAM.

Windows successfully diagnosed a low virtual memory condition. The following programs consumed the most virtual memory: explorer.exe (7612) consumed 14535200768 bytes, bg3_dx11.exe (8640) consumed 12646260736 bytes, and firefox.exe (3024) consumed 693784576 bytes.

-Prep