Include font once

I am currently allowing each user to pick a font per tag i.e. H1, H2, H3, etc.. in the theme admin area using the plugin. The problem is that multiple fonts of the same type, result in the font being loaded multiple times by the client. Can duplicates be filtered before being output in the wordpress header?

Blocked loading mixed active content “https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,400,600,700,300”
Blocked loading mixed active content “https://fonts.googleapis.com/css?family=Nunito:400,300,700”
Blocked loading mixed active content “https://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,400,600,700,300”
Blocked loading mixed active content “https://fonts.googleapis.com/css?family=Nunito:400,300,700”

https://www.ads-software.com/plugins/acf-google-font-selector-field/