wormhole is awesome, useful especially in ad-hoc scenarios. I use it often to copy files between systems when I can’t use scp (because of no relevant entries in authorized_keys.
The protocol enumerates all the IPv4 addresses on each side, and attempts to connect to all of them, and the first successful handshake wins.
So if your VPN arrangement enables a direct connection, `wormhole send` will use that, which will be faster than going through the relay (and cheaper for the relay operator).
A basic VPN gets you safe connectivity between the two sides, but transferring a file still requires something extra, like a preconfigured ssh/scp account, or a webserver and the recipient running `curl`/`wget`. magic-wormhole is intended make that last part easy, at least for one-off transfers, just `wormhole send FILENAME` on one side, and `wormhole receive [CODE]` on the other.
Right, I'm more commenting on the "have my friend slurp files" part: that sounds more like they want to set up a VPN with normal file sharing (e.g. full network shares) so their friend can just grab literally anything as long as it's in a network share. It didn't sound like they needed individual file transfers.