The draining liquidity part is so real. It happens very very quickly lol. I wasn't able to use your swap service for even 100k sats the other day. The dynamic fees route sounds the most logical to me. That way, it will protect the last remaining liquidity from unnecessary usage and only allow nodes who actually want to use it meaningfully. I think zero fee routing (the node) disables the channel altogether itself when they don't have more than 50% on their side (they might have changed this strategy now, not sure)