The issues are most likely different manifestations of inaccurate CPU timing, the way that asynchrous HLE desyncing different problems in different games that are all solved with new-AX-HLE or LLE. But this is CPU. I think the issues are different enough that they should not be in the same thread. But it is a real issue, if what you're experiencing is true.
Also, running background tasks is a valid way of producing stress, save states can cause problems. Those problems are part of the savestate system, not the engine. Savestates may be able to expose engine issues, but I don't think it's always really valid to use them.
Also, running background tasks is a valid way of producing stress, save states can cause problems. Those problems are part of the savestate system, not the engine. Savestates may be able to expose engine issues, but I don't think it's always really valid to use them.