5 in the morning and I finally figured out wtf is wrong with Dopamine jbupdate. Turns out there has been an OOB write on a kernel pointer for the past 3 years but until now the allocation was always large enough to tank it. In Dopamine 3 I switched the allocator to one that only allocates as much bytes as needed, leading to this OOB write now smashing the next element on the heap, which can lead to all sorts of panics. Also notably the "Failed to update BaseBin" corruption issue is caused by this, since the specific file that's usually corrupted is written to right before the broken code is called. So if the broken code panics immediately, this is what causes the filesystem corruption... How a 3 year old bug can bite you in the ass...