How can I only show the label if/when the command is defined

[gwash]

I'm trying to set pretty labels for plugin commands that are only available under certain conditions, like a filetype or a mode, but whenever I register just the label, it shows up regardless of whether it actually does anything. Example with nvim-orgmode:

this shows up like this:

"Insert" here (i.e. not inside a .org file) doesn't do anything, and in fact would trigger an error if I pressed it.

[ArcusCerebellumus]

I don't understand why you need them predefined... maybe, just define maps only when you need them(?):

vim.api.nvim_create_autocmd({...},{
    -- extension pattern is an obvious take her, but there might be other options
    pattern = '*', 
    callback = function()
        -- here you call, for example,
        require 'which-key'.register(maps, opts) 
    end,
})

You can also do a similar thing to UNregister them.
If you use nested = true you might even pull off automatically unregistering them when you enter any other pattern (not sure, though)