It would break the 72(t) and you'd be liable for penalties.
Also, if you read the rules on Roth conversions, they specifically say that you cannot use 72(t) distribution money as a source for Roth conversions.
Basically if you start a 72(t) on any account, you can't do anything else with that account except the 72(t) distributions until the SEPP is done.
"At times the world can seem an unfriendly and sinister place, but believe us when we say there is much more good in it than bad. All you have to do is look hard enough, and what might seem to be a series of unfortunate events, may in fact be the first steps of a journey." Violet Baudelaire.