In coinos.io ( nostr:nprofile1qqs9vmqkduad4vxglwja5q2mpvauer4nd9452he2r4pml0vhqktyd2qpzemhxue69uhhyetvv9ujucm0d9hx7uewd9hj7aqfmp9 nostr:npub1w27mc4aa6m0ufe3xs5z3m6qyr52gc0rglept7vqlwx4xeaf72tasnqz70r ) everything is integrated on the back end: on-chain, lightning, ecash and liquid. Not sure if it retains the properties calle mentioned here.
he fee to exit on-chain is 0.4%; not 100% sure.