Are u talking about the guy who is blocking 21122 pr the guy using 21122?
Im pretty sure the point of jumping at any point in the string is to deter the command grab from connecting. we know it jails if you ride the string out to the end. Im just saying that instead of just releasing block and taking the last hit to make the ex-sand whiff, why not just jump out before the string finishes. That way, if they do command grab or ex-sand, they will get whiff punished. if your wrong, you take the hits like u intended.