I just tried this and looks like cbrpager introduced new mime type 'application/x-cbr' (in file manager tap-and-hold and choose details to see that mime type)

That mime type doesn't show up in the defaults tab though so i will have to add that mime-type in the next release.

You could add it to defaults.list yourself but probably easier to just pickapplication from list and choose dbus-switchboard (or maybe even cbrpager)