I have thought about this a lot already and basically came to exact same conclusion with the "bubble" system.

But don't the bubbles have to tick at the same time to be 100% vanilla? They still compute their ticks independently but only "roll over" together. Which would still increase performance extremely, don't get me wrong. But will not stop lag machines, since global mspt would be the min of all bubble mspt's. Although it would make tracking lag generation a lot easier.