straight-vc-git-default-protocol is currently a global setting. We can define either ssh or https for all hosts. Users who have SSH keys for GitHub but not for GitLab or Codeberg are forced to add straight-register-package overrides for every package hosted on non-GitHub forges.

For example, with the recent zig migration, although melpa defines the formula properly, current workaround required a per-package override:

(straight-register-package
 '(zig-mode :type git :host nil
            :repo "https://codeberg.org/ziglang/zig-mode.git"))

My feature request is to allow straight-vc-git-default-protocol to accept an alist mapping hosts to protocols, falling back to a default:

(setq straight-vc-git-default-protocol
      '((github . ssh)
        (t . https)))

(Note: might be better to call it like straight-vc-git-default-protocol for backwards compatibility?)

Or better yet separate variable:

(setq straight-vc-git-host-protocol-alist
      '((github . ssh)
        (gitlab . https)
        (codeberg . https)))

I think the alist approach might blend seamlessly with custom hosts.

Either approach should eliminate the need for per-package recipe overrides when the only issue is the protocol, not the repo location.