If you have time to keep re-directing then it will keep you in the air for longer, just be carful not to send the kite too low or you could hit the ground with speed. I usually find that holding the 're-direct' for as long as possible, ie, before the kite starts heading towards the ground, gives the best hang time. If thats not enough then you probebly want a bigger kite or better conditions.
I remember wondering why my 4m blade never gave much hang time, and tbh is never has; small kites lift big and dump hard, if your after float you'll probs want a 6.5 blade.
Im still saving up for an 8.5m blade IV so i can experience the floatiest jumps of all...