[ironic_monkey]

i think that bit is up to the kodi core right now, you launch the rom like you would launch any other media, and if there are multiples you get a menu like you get with 'play using..', with an option to set defaults to avoid the menu. i don't think it makes sense to leave it up to add-ons to handle the player selection stuff.

wait for garbear to comment though, this is just a somewhat-educated guess.