Can't use settings on customcss anymore (3.9.1.4)

I was trying to upgrade from theme_adaptable_moodle39_2020073110 (3.9.1.3) to theme_adaptable_moodle39_2020073111 to (3.9.1.4) and kept running into the "all" stylesheet hanging when it had to be generated for 3.9.1.4

After doing some tests I figured out the problem is I'm using settings inside the customcss setting, like this:

.course-content h3.sectionname {
  background-color: [[setting:coursesectionheaderbg]];
}

I don't fully understand how to fix this but I think the issue originates from changes on lib.php with the old function being theme_adaptable_process_css and the new functions being theme_adaptable_process_customcss($THEME->csspostprocess) and theme_adaptable_process_scss

I don't have access to old adaptable versions of 3.10 and 3.11 but I think the newest versions could have the same issue