I wonder, as well. And I really do not want to disable half my modlist, test, re-enable, test, etc. Especially with my modlist as big as it is (which I just checked my plugins on Vortex and it's comfortably sitting at about 323, so I probably have way more than I thought). Also, the bug happens like... 10-15 minutes into the game and I don't even know how to trigger it, but I think it has something to do with dialogue or custom NPC voices. Only custom followers I have is Inigo and Thogra, right now, but I also have 3DNPCs. Then again... that same thing happens with Arngeir and other in-game NPCs, so... might not be that.
I think what I'll do is delete a good handful of mods, delete the Engine Fix, start a completely new game, and see how things go. If I notice any stuttering, crashes, etc. I'll install the Engine Fixes again. Then, if I keep getting the save corrupt bug, I'll probably purge all my mods, do a complete reset on everything, and start fresh with my modlist. Which... I am not looking forward to doing.