Ah yes you're so right, a 'distributed' synchronisation method could work great!

I love the idea of mechanical sensing too! Would be cool if somehow the 3-neighbour 'grow' rule could somehow involve budding off a cell from the (or one of the?) 'parents' and transitions from 1 to 0 (cell death) could actually involve the disassembly of something! : )

Since GOL doesn't consider the self-cell, there are 9 possible values for the 'total' (0 to 8), and since there's both Birth and Survival, that's 18 bits in total, so 2^18 which comes to 262,144 possible rules! That is a LOT more than I thought there were! Cool! - makes me want to explore them again more thoroughly.