I just found this plugin within the past couple of weeks and i really like all the options/settings it has but have run into this small issue where one of our CSS variables are getting converted to lowercase. hoping there's a fix rather than have to re-write a bunch of html code in various places to work around this quirk. The CSS vars like --PDF-blue where its CAPS-lowercase for the names don't seem to be affected.
Linux 4.19.286-203.ELK.el7.x86_64 x86_64
Apache
php: 7.4.33 (Supports 64bit values)
php sapi: litespeed
LiteSpeed: Version 5.6 standard/free
CSS minify, combine, Combine External and Inline, and Inline CSS Async Lib settings are turned on, all other css settings turned off.