This question arouse as I tried to process a payment and created a lightening invoice in one wallet and there was a fee number mentioned. Then when I tried to process that invoice through my @getalby wallet it wouldn't let me unless I left 1% of the sats of the payment I was making. (I was trying to get all funds transfered). The 1% was 4-5 times higher than the fee the other wallet mentioned. So it got me curious.