I've deadlaunched a Flashback as well with out problems. However I do remember once when I cracked a stand off in half doing this.
I don't do many deadlaunchs now, as I dont' want to crack/kill/destroy any part of my kites for the sake of 30secs and a short walk down the field.
I usually use 'the walk of shame' as a good time to check over the kite, like a flight inspection. I check the bridle to see if it's wrapped or something, I check the spars to be sure everything is still plugged in good and not ready to fall out. Then I check the sail tension and the lines around the nock.... etc...
then back into flying position if everything is in order... and back into the air!
I've turned the 'walk of shame' into a 'flight inspection test'

cheers,
Dean