Crouching in DOA "takes time".
How long does it take is shown in the skill info page 3 under the switch frame section, which usually varies between 4F (very slow) to 1F (instantaneous). Based on how little we know about this bogus value, it might as well be decided by magical incantations.
So...
Delaying 7PT on block can abuse the idle/unholdable frame bug and create a 50/50 situation.
OPTION 1: delayed 7PT
You want to land the T on the idle frame that comes right after the enemy blockstun animation. The defender CAN NOT INPUT any throw, hold, side step, charge attack, can't crouch...