currently, when making a payment, the fees are being added to the amount sent.

for instance, if someone want to send 10,000 sats, and the fees is 2,000, the total will be 12,000 sats.

the issue to do a send all is that, when the base amount increase, the fee might changes (fee are being calculated dynamically by lnd).

so for instance, if someone has 15000 sats. he would need to have maybe 13000 sats in the amount, and if the fees are 2000 sats then this would send all. but maybe for 13,000 sats the fees would be 2050 because one utxo is being used. and for 12950, only 2000 would be necessary because a single utxo would be needed.

so empirically people are doing a dichotomy to find the right amount to swipe their balance. I believe the right way to manage is to have a send_all flag where instead of the fees being added, it should be deduced from the total amount sent.

this would have an impact on the react native side. but first the API should be available for consumption to the mobile wallet.