This code path requires gokrazy/tools at this commit or newer:
37e2f95c5c
And gokrazy/serial-breakglass at this commit or newer:
bf9bc19235
Afterwards, with an ~/.ssh/config entry like this:
Host scan2drive
ProxyCommand breakglass -proxy %h
…using Emacs TRAMP should just work:
emacs /ssh:scan2drive:/perm/keep/index.md