Björn Bidar wrote:

Also, the wmctrl solution requires the package to be
installed

Same for any other external solution such as your
recommended solution devilspie2.

Of course, for the external solution to work you need the
external solution.

A solution that is external but maybe feels more integrated is
to have the window manager maximize the window, should be just
up its alley.

One can also have the window manager execute external
commands for that matter. Here is an example for
openbsd-cwm(1) which I use on Debian

  https://dataswamp.org/~incal/conf/.cwmrc

As I told Björn earlier:

    I'm happy to inform that Chat just solved it without external programs, see the mail with subject "Re: Solution to a proposed FAQ, how to maximize emacs quickly (like `emacs --maximize`) for GNU/Linux - Improved solution by Chad: ~/.emacs.d/early-init.el"