Isn't the executive order 6102 risk there, regardless of whether people self custody or use custodians?
As long as there isn't very widespread adoption, with a relevant fraction of voters/lobbyists (say > 15 %) holding Bitcoin (custodially/non custodially), then a state, seeking to get a sound basis for the coming monetary paradigm by building a reserve, will just issue a 6102 order or make holdings unviable by imposing an astronomical unrealised capital gains tax.
Many people will comply, unwilling to leave the country. At least that's what I'd expect to happen.