Conditional settings using visible_if are live https://shopify.dev/docs/storefronts/themes/architecture/settings#conditional-settings
So it should be feasible to make an “advanced mode” or “developer settings” setting as a boolean etc.
But like most things there are undocumented limitations and lack of parity in different systems being found like incompatibility with app-data metafields, dynamic sources, and pretty sure things like custom-css settings are just gonna always be off the table etc etc etc.
See these discussions Online Store Editor - Sidebar & Conditional Settings · Shopify/reference-theme · Discussion #46 · GitHub
& Visible_if doesn't seem exactly compatible with dynamic data sources