I wondered how many actions a custom block can do per second with the run without screen refresh setting on this will average out 50 runs to be averaged out by 49 other averaged runs this will take 40 minutes and 40 seconds to be completed (yes I did the math) tell me your results in the comments
This counts how many variables that a run without screen refresh can change in a second so, it may not be as accurate if there are more blocks in the custom block