This kind of thing is used often to fine-tune the weight of different paths in levels (such as long hole levels and linked lock levels) with many trips. Good insight.
3x10 is hard to compose puzzles for. You might find it useful to look at the hardest puzzles in this restriction and see if they inspire you:
Insular Dwarfism, Swan Song, Typhus Fever Shananagans, Vanilla Extract, Vanilla Extract II
Insights