Well you're not going to see it in a basic exchange app wallet is my point. Not because it would be impossible, but because most people wouldn't understand what's going on and it would be more work than necessary (Relai won't care, that temporary wallet is just to hold Bitcoin for the moments before you safely send it out, only there to allow Relai to abide by Swiss Communist law)

Do it often enough though, and with one UTXO to one output, you'll know whether you're paying 2000 sats, 3000 sats or more... Roughly.