I got a bit confused. Also, answering your question, I mixed up a bit by indicating the wrong type of error. But generally, when a payment cannot be sent further because, for example, we don't have enough balance on our side to send it further, an onion is also sent, which indicates a temporary error code, and the onion is also sent back to the sender. From it, they can see which node along the way sent it, so they don't send the same-sized payment through the same channel again.

Actually, I was talking in the context that instead of specifically regulating fees in channels that are drained, you can just rely on such packets to be sent to the sender if the payment cannot go through due to insufficient liquidity. And if there is still enough liquidity to make the payment, even if it's small, let such a payment go through at a fixed rate that was there at any balance of our channel. I hope I expressed myself more clearly.