Yep, that's on me - there was a check which prevented pulses from continuing through tiles they'd already passed through, but I unknowingly broke it immediately before upload and was far too sleepy to notice. I have ideas for lots of unique nodes - ones that would change pulse types to a healing pulse or a chaining lightning attack, for example - but spent too long refining the node-to-node communication system and ran out of time.
You're totally right about not rotating, that could potentially solve a number of problems. Thanks for the suggestion, and thanks so much for playing!!