This is really clever! I'm not particularly tech-savvy, so I didn’t know about this until reading this thread. The ability to connect your hardware wallet, like Trezor, Ledger, etc., directly to a decentralized exchange is brilliant, especially if you want to avoid CRS or other reporting in the future, as it lets you stay completely out of the publicly monitored system.
However, I also don’t see how OP managed to exchange cryptos for 700 euros. For 100K euros, it costs around 80 euros to exchange, depending on which crypto you’re swapping from / to.