T3539
Cashtab has used 550 sats for the "min send" XEC value and actual dust (546 sats) for token outputs. The original rationale for this: bch-api was not great at separating token utxos from non-token utxos, and this provided another fall-back insurance on separating utxos.
Was a bad "solution" at the time and really should be out by now.