> The global minor mode commands you bind could just
> invoke a minibuffer key binding
How? What I'm trying to do is avoid overriding a minibuffer key binding established by another package, which I don't control.
> if you don't want the global minor mode to have
> _any_ effect in the minibuffer
No, generally the desired behavior for these use cases is that the keybinding will by default be active in the minibuffer, unless minibuffer-local-map happens to override that key, in which case minibuffer-local-map should be preferred.
> is it only about key bindings
That's the problem I face, yes. Per my above comment, just conditionally disabling the minor mode doesn't actually solve the problem. Unless you were to conditionally disable it by scanning minibuffer-local-map for a specific set of keybindings, which feels somewhat horrifying.
More generally though, it would be really nice if there were a way to specify the numeric priority of a keybinding. Currently, minor modes are unconditionally preferred over major modes and minibuffer bindings, which are unconditionally preferred over global bindings. Usually this is what you want, but when it isn't, the workarounds feel pretty hacky.