@d-healey Some fonts are multiligual and since they are also including non-Latin char sets they use wider metrics. This may end up with different scaling on the different Operating systems. I see that issue especially on the Devanagari type fonts which means they may need to have larger vertical metrics than ordinary Latin fonts, due to stacking conjuncts and mark positioning. This issue also happens on the different web browsers too.
Maybe getting the Latin-only versions of the fonts (if you use only Latin chars in your plugin) could help but I am not sure if it works for every font.
If it is a Google font, you can get Latin-only versions from the Google Webfont Helper here: https://google-webfonts-helper.herokuapp.com/fonts/poppins?subsets=latin