If a Flatpak application ID is passed in as an argument (--args) to systemsettings or kcmshell, then this KCM will try to load in requested application page when it's first initialized.
The plan is to implement scrolling down to and focusing on a specific permission row(s), so doc comment mentions that in advance.
Unfortunately, due to limitations of KCM API, it is not possible to request a different page on the fly, without having user to unload KCM (switch to another one) or fully close System Settings app. Hopefully, this will be revised in KF6.
In order to be able to implement that, I had to expose some more properties and enums from models and classes.
Relevant patch in Discover: discover!466 (merged)