I reproduced original pcb from Tom Whitwell and build several.
After a lot of testing and measering I found a good balance for lock and unlock!
Poti middle position = random
right lock = loop
left lock = loop and inverting (8+8, or 16+16 steps),
Length = 8 or 16 Steps
Write down Low, up Highs
…. more info: random-sequencer-documentation-v2-1