Please help us help you and fill where relevant:
Your LimeSurvey version: 6.5.3
Own server or LimeSurvey hosting: own
Survey theme/template: custom
==================
6 years ago, there was a forum thread about adding font packages. Has this been developed?

Adding new font - LimeSurvey Forums

I would like to add some fonts for customers

It can already be done via theme editor directly ? No ?
You want something with a dropdown ?

In this case : my opinion : do your own dropdown and system (like i do for variation)

Thank you. Do you have a working example that I can try & evaluate?

Tammo

No,

The idea

1. Put your new fonts in files/fonts directory of theme.
2. Create a dropdown option selector ( something near this ? Never done myself)
3. In an header part : register the needed css file according to choice done : gitlab.com/SondagesPro/SurveyThemes/skel...ws/header/theme.twig (the is due to this issue : bugs.limesurvey.org/view.php?id=17858