Clearification about Firefox and KDE compatibility

Hi lovely people

Reading the docs about Firefox, I see this part about KDE integration:

Now, the references source (The Arch Wiki) speaks also about one setting specific to MIME types.

To use the KDE file selection and print dialogs in Firefox 64 or newer, install xdg-desktop-portal and xdg-desktop-portal-kde, then set widget.use-xdg-desktop-portal.mime-handler to 1 in about:config

So, is this recommended as well?
Should we add this setting to the documentation?

I am uncertain, if I understand well, what the implications of MIME handling are.

And to add up to the confusion, the source further quotes:

For integration with KDE MIME type system, proxy and file dialog, one can use (…) a symbolic link to the MIME database ~/.config/mimeapps.list from the deprecated ~/.local/share/applications/mimeapps.list

So, now I am entirely confused. I thought the setting widget.use-xdg-desktop-portal.mime-handler already does that?

Our doc at Nix does not speak about this at all, so I am uncertain what leads to the best result.

And what is with the other three settings, are they of any use as well:

widget.use-xdg-desktop-portal.settings – Whether to try to use XDG portal for settings/look-and-feel information
widget.use-xdg-desktop-portal.location – Whether to use XDG portal for geolocation – Whether to use XDG portal for opening to a file