I know what you mean and to be 100% sure, we would need to look at these fiat TXs and btc TXs if they all pair exactly….
I don’t think so, they buy bitcoin in big the pool way rather, than tx for tx. That is also why it takes some time before you get bitcoin in your wallet, not directly.
My theory …
Data proofs would be:
My Fiat for Relai fiat
Relai btc wallet Tx to my btc wallet.
I don’t think that robo sats is like a way better bc you still use revolut or other fiat payment the same way.
But true is, in worst case, auto robo sw is worse to audit than standard relai business …