This isn't a mod order problem, it's become an issue with the save itself.
I had an autosave and a quicksave of the same run, both of which would crash on exiting a cell, saving or waiting. My much earlier saves didn't- so I know its a corruption problem.
I found that using a nuke to blow myself up would allow me to leave and save, but after a few minutes the problem would start yet again. Also I get infrequent crashes now when just moving around.

I've also tried deleting auto and quicksaves and redoing- and creating a new save file for that run.

So far I haven't been able to fix it, does any remedy exist?