Add minified style.min.css with top commenting in tact.
Enqueue style.min.css in site always, no matter if using child theme.
If child theme active, enqueue child style.css after.
Custom CSS output will need to proceed correct style.css. So use condition that check if child theme is active or not before designating attached stylesheet for wp_add_inline_style(). -- This part will be different for each base and Gnar and Denali; so implement carefully.
wp_add_inline_style(). -- This part will be different for each base and Gnar and Denali; so implement carefully.