bug#45054: 27.1; Can get point into the middle of a run of characters with a replacing display spec

[Eli Zaretskii]

> Date: Sat, 05 Dec 2020 18:18:15 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 45054@debbugs.gnu.org
> 
> > 4. Is there a better way to do this sort of visual replacement of runs
> >    of text?  This is the first time I’ve done any serious elisp
> >    programming, I might have missed something.
> 
> Sounds the right way to me (modulo making the text invisible).

As an alternative, you could try the technique used by
prettify-symbols-mode.