bug#61227: 29.0.60; Customize UI for customization of keys

[Drew Adams]

FWIW (caveat: I'm not following this thread):

If defcustom type `key-sequence' is being used,
you might consider doing something like this
(besides, yes, making clear what `key-sequence'
requires as input - which really should be done
for all uses of that type):

Let users provide either what `key-sequence'
expects (a key description) or the symbol of a
command to remap.

I use this, for example, as part of defining a
`key-definition' widget based on `lazy':

(choice
 (key-sequence :tag "Key" :value [ignore])
 ;; Use `symbolp' instead of `commandp', in case
 ;; the library defining the command isn't loaded.
 (restricted-sexp :tag "Command to remap"
  :match-alternatives (symbolp) :value ignore))