Well, maybe but all TVs I have/had here in Poland (Sony Trinitrons, Philips, Samsung, Elemis, Thomson) didn't support arcade_15ex extra modes. Only once (I don't remember exact mode or even TV I used) I saw working mode but with distorted picture. One mode did work but picture was bad.
Anyway, every TV I had/have (except polish Elemis - PAL only) supports fully arcade_15 modes.