The idea may not be bad, but it seems wrong to me, at least when it comes to privacy-focused (instant) exchanges.
Saving the deposit address would require some kind of log or similar record, and that is enough to cancel the no-log policy or no holding user data.
Thats a good point. Perhaps it would be better to think of it simply as a floating exchange order with a
long time limit, and preferably accepting multiple deposits. I think its necessary to persist
something to disk during a trade anyway (and then promptly purge it), or else funds would be lost in case of a system crash.
I would certainly always trust the wallet that I control more than leaving it all to a third-party service. At least to the greatest extent.
Trust-based systems are always problematic. But the service they already have is already based on trustoh, trust, and PGP-signed guarantee letters, and escrow.
It must be emphasized, I dont want anyone to hold coins for me! What I seek is
strictly noncustodial. I keep coins in my wallet
my keys, my coins. I just want to set it up so that when someone sends me BTC, I
automatically receive the same XMR (later ZEC) that Id exchange to manually, if I bothered with a Bitcoin wallet.
As long as I have the PGP-signed guarantee letter, blockchain data on the BTC side, and my own wallets data on the XMR/ZEC side (which could be revealed to others with per-transaction view keys in case of scam), theres no way they could get away with cheating me. Trust is minimized on the basis of,
Trust, but verify.