Hallo Hello + Hola Manuel,
I'm a longtime CA-X30-user and follower of this forum here, so I was also confronted with these unsolved questions like sorting i-radio-favorites; unfortunately it seems there is no comfortable solution up to now.
Since years I use my own method for sorting the i-radio-favs, at least for the i-radio [reciva] - stations (its not working with airable):
step 1: I use special characters to bring my absolute favs to the first places, for example position the asteriks "*" or "#" or a "." (point), two or more points "..", "..." as first characters of the station-name.
Howto: mark your stationname > menu > rename > save. (Use of an usb-keyboard makes it easier!).
BTW: you know that the "sort"-key on the rc is also active AND that you have some editing capabilities in using the web-interface?!
2. step, with the same method as above I classify the stations after "genre", f.ex. choose a "C" for a classical station; or a "T" for "Trance" = C+stationname, T+stationname etc., etc., or you just number the genres and use this number as first charakter of the stationname, you just use your own preferences; if you didn't found out yourself already, try it.
Of course you know, some functions and possibilities vary with the firmware-release and/or the model. If the one or other idea was useful for you, pl. let the followers of this forum know. Apart from that we all wait for some smart solutions by the manufacturer in this + other questions!
In the meantime: enjoy the music with your CA.
Greetings from Hamburg, Michael