So I found this while running the game the first time but selfishly kept it till now.

So in any of the level menu's you can select the levels using the numbers 1 through 6. The first level isn't assigned a number key, probably because that is where the curser restarts anyway. You can also do the first level of the next laboratory using the 6 key.

Possible uses?

A large one I thought of was kind of RNG manipulation where we can restart a level till a solid amount of blue is at the start.

This would mean doing research into the most efficient blocks(idk what to call them) are for each level would be a major help

I was not aware of the numbers for level-select. Thanks for the tip!