the reason to backup the cache is so you don’t have to remake all the depth maps.
but sounds like you issue is there somewhere. I don’t normally get crashes at that stage. so its hard for me to know.
I would check your alignment, dose any the of the sparse cloud look wrong?
might be worth disabling any cameras that look like they could be an issue.
and since your having problems with depth maps it might be worth clearing the cache (all that work will need to reprocess though). but if you can store it somewhere else at least until you work out whats going on. you may want to bring it back.