I've tried Dullcoat, and it sorta works, but not as well as I hoped. Maybe I didn't let it dry enough, I dunno.
But yeah, this is the one thing I can't be bothered to make until I get better directions than just "spray". I've tried it twice and they decks came out OK, but not as good as the one I bought.
I say just spend the couple of extra bucks and buy it already made. And yeah, you can't get a guardian/centurion/etc ID, but performing with anything but regular bikes attracts too much heat. They're going to want to inspect the deck THAT much more and an ID ends pretty dirty unless you do a clever deck switch.
So yeah, that's my general rule of thumb - if the deck is going to be gaffed or have a gaff, it's definitely gotta be a regular bike deck. If I'm doing something where the deck is inspectable before/after the trick (something like an ACR) then it doesn't matter so much.