Add-on compatibility issue in recent Firefox web-browser versions

[The-First-King]

The "Fit Text To Width" add-on functioned well in Fennec-based Firefox versions up to 68. Since the transition to the GeckoView engine in Firefox 79, it has been discovered that this add-on no longer performs its primary function of adjusting text to fit the screen width. Could this add-on be reviewed to ensure compatibility with the current engine?