When I use ctrl-z after doing something that causes a butterfly effect such as pouring acid over a electronic, the simulation gets really messed? Also when i do ctrl z after any modification to a subframe save(even without doing modifications to the thing at all), the tech gets messed up aswell.

An example could be undoing anything in synergy computer save, if the printing is active at the point of modification and at the point of undo the letters get stuck. and in subframe it is some stuff getting non subframe(regular spark can be seen).