I have made a minor mode for texinfo that does this, but the buffer
is not being returned to look as source code.  They still look that
they have a difference in height.

I attach the file with a test.


> Sent: Wednesday, February 10, 2021 at 3:53 PM
> From: "Michael Heerdegen" <michael_heerdegen@web.de>
> To: help-gnu-emacs@gnu.org
> Subject: Re: tex-mode.el
>
> tomas@tuxteam.de writes:
>
> > You want to change display back-and-forth? Have you tried invoking
> > (font-lock-refresh-defaults) after changing the variables?
>
> Even calling (font-lock-flush) should suffice, since
> `tex-font-script-display's value is consulted on the fly.
>
> Michael.
>
>
>