Re: "whether the global keymap C-x 4 will be replaced by a command,"

[Juri Linkov]

>   > Would it be more expected for `C-x 4 C-h k C-f` to show the help buffer
>   > about `C-f` (forward-char) in another window?
>
> For consistency, C-h k C-x 4 C-f should show the help for C-x 4 C-f.
> That is find-file-other-window.

A special handling of prefix commands could be added to the
implementation of 'C-h k'.

Then instead of saying that the command is 'find-file-other-window',
it could say: "the command is like 'find-file' but displays the buffer
in another window."

> C-x 4 C-f is an important command -- don't break it!

Its effect should remain the same (displaying the output buffer in
another window), but the command namespace will be cleaner by removing
duplicated commands with '-other-window' and '-other-frame' suffixes.

Also it should allow the users to add the effect of displaying the command
output buffer in another window to more commands easily, by just adding
a key binding to the existing non-window command in the 'C-x 4' keymap.

Anyway, before changing the 'C-x 4' keymap we could try this approach only
on project-specific submap 'C-x 4 p' to see how well it works.