How to speed up the simulators?

[Lapayo]

Well, the simulator isn´t slow. But I think C++ could do much more speed. When you throw an 20 * 5 Sand plate in the ocean for example (With the old sand wakeup, where all blocks around are notified) it starts to lagg heavily. The Core goes to max and Ticks are taking more than a second. I think in this case the duplicate-check takes much time (Like mentioned somewhere else, it could happen that more than 3k Blocks are moved into the queue. And when adding a new block it iterates for each block through all tousend blocks and also adds a new one and then again and again
I already switched to list because I think it should be faster then vector when adding many items to it.

Another problem I saw is that blocks which get destroyed under water sometimes never leave the simulation queue. (Only occured when the block is destroyed under flowing water, not falling or stationary)
This also causes some lagg because every tick their flow gets calculated again and again but nothing changes