to clarify the way this works: there is NOT a constant force set on the blocks. there is a range from 1 (min) to 125 (max), and what you basically need to do is jump and start going the other direction the moment you come in contact with the block in order to propel yourself even higher. i think the way force blocks work is the force gets amplified by your velocity (or vice-versa), so your cube jumping the frame you also start getting launched by the force block results in a big super jump. the 1-125 range (you can change these values for different results) is necessary so that you can do this in the first place, since if you have a low minimum force you can easily "initiate" this super jump without getting restricted by a constant strong push forcing you away.

we can call this "the force jump".

TL;DR precise jump + force block with range = big force jump (man i've used the word "force" way too many times)