I would prefer to use PGP encryption since I can decrypt the message on my airgapped device.
Good point, that is more secure.
everything is in the open and to minimize any risk of scam accusations from either side.
That's a fake sense of security. I realized the same when offering my Fork claiming service: if either one of the parties moves the funds, it's impossible for the other party to prove anything. So it really comes down to trust.