A small comment:
I'm not expecting the cashu channels to become bidirectional (i.e. like LN-Penalty)
Or more precisely, even if someone implements bidirectional (something I've thought about a lot),...
Thanks for clarifying @SatsAndSports, I wasn't sure whether to call it a Spilman channel or not. Either way, an efficient way to transfer money in both directions would be really useful regardless of whether it's two Spilman channels or a single bidirectional channel.