So maybe the solution is to double-send all the encrypted packets - once to the VPN endpoint, and once to the original target (but encrypted so it doesn't reach

So maybe the solution is to double-send all the encrypted packets - once to the VPN endpoint, and once to the original target (but encrypted so it doesn't reach). Or maybe instead of the intended target, to some randomized selection of targets. You wouldn't get responses, but maybe that doesn't matter.