I can get into why that's a waste of time separately, but let's say you do that - why don't you just use lightning network for the transfer and routing and swap the coins in the wallets for whatever each side desires? That's possible today without changes.
The interesting thing about lightning network is that as soon as sender and recipient confirm that they received what they wanted, the transaction is settled. They could transact cows or bubblegums and the lightning network would settle those.