Disable GTK & QT Theming

[timboydon]

Is there a way to disable theming of GTK and QT applications?

For GTK applications I can seemingly just keep the option "apply this theme to GNOME apps" disabled, but it doesn't seem to reliably remember my choice.

For QT applications this doesn't seem to be in the settings panel, so hoping it can be controlled via the configuration files.

For reference, I'm using cosmic (now upgraded to alpha 6) on NixOS and would like to use Stylix for system-wide theming, but cosmic is not supported, so just trying to avoid conflicts.