I made this thing in turbowarp, which is why the code when viewed on scratch is a bit messy (it seems turbowarp grid snapping doesn't work here and comments are now hidden behind the blocks) Regardless of that, this is some code for managing a list representing a multi dimensional array. I don't think it's too great of an idea to implement this for something, as often more custom made solutions have better performance, but if you just wanna mess about with a 6D list or smt its nice. Beware however that a 6D list of 10 by 10 by 10 by 10 by 10 by 2 items has length 200 000, which is the limit on scratch.
I made this thing myself, inspired by Haycat2009's question on https://scratch.mit.edu/discuss/topic/903808/