As a data point have just booked 2 redemption tickets to Oz on QR via Revolut. I have a metal card so €595 outlay returned 5,200 in avios. Was a bit dubious when I had to transfer some avios from BA to QR in middle of the booking as well as authorise the Revolut payment and wondered if all the back and forward would cause it to fall over but it didn't.
With regards to protection raised by woobl above, I don't know the answer. I will say that I have bought a number of tickets with both EK and QR out of DUB in euro using Revolut and never had an issue , but I may just have been lucky.