Wow, I was just playing around with the new version of nak by @fiatjaf , with it you can create your bunker in seconds to sign remotely on any client that supports nip-46. Just download the utility from the 
repository, there you will find instructions on how to run it, once installed use the command `nak bunker --prompt-sec wss://<relay-url.com>` to start the bunker with the relay of your choice as coordinator, then once it has run it will ask you to set your nsec, after that you are all set to sign messages remotely using your own bunker!
I have recorded a short demo
GitHub
GitHub - fiatjaf/nak: a command line tool for doing all things nostr
a command line tool for doing all things nostr. Contribute to fiatjaf/nak development by creating an account on GitHub.