Nahnu Fonts → Settings has two groups. Settings changes are saved together with the Save settings bar that appears at the bottom once you change something; Discard undoes them. Tools (Adobe Fonts, Import and export) act right away and don’t need saving.
If you leave the page with unsaved changes, your browser asks first. Switching to another Nahnu Fonts screen keeps the changes until you save or discard them.
Where Google Fonts are browsed and downloaded from in the admin: Bunny Fonts (GDPR-friendly mirror, EU) or Google Fonts directly (needed for variable files). Visitors always load your copies
Default character sets
Latin
Pre-selected sets when you add a Google Font: Latin, Latin Extended, Cyrillic, Cyrillic Extended, Greek, Vietnamese. Changeable per font. At least one is required
One switch per supported builder or theme that is active on your site. Turn one off to stop adding your fonts there. Builders that aren’t active are listed underneath
Every setting has a key, for example font_display or builder_google_fonts_off. Use wp nahnu-fonts setting <key> <value> or the nahnu_fonts_settings filter. See WP-CLI and Hooks in Developer.