It was mentioned years ago it should be some blog post re custom fronts tips and tricks.
Here's a blog post by HermoT with some general stuff as well as some of his tricks:
https://developer.garmin.com/index.php/blog/post/connect-iq-pro-tip-custom-fonts-tricks
Unfortunately that link doesn't work any more. Could someone provide an actual link or even more updated custom fonts tutorial(s) or guide?