Multiple destinations

Those are non-sequiturs.

What makes Revolut’s rate inherently better than MasterCard’s rate on weekdays?

Why does the locking of a rate after the transaction make any difference to how good the rate is? With both Revolut (doing FX at time of transaction) and MasterCard, the rate is locked after the transaction. With Revolut, it’s immediately afterwards; with MasterCard it’s a day afterwards. In both cases, you’re equally at the mercy at whatever the rate is at the time the FX is done. Both have an equal chance of being better.

See Result of test/comparison of FX rates across 4 MasterCards including Revolut