Hit the jump in the meat of the power, not max RPM and not bogging it. They would only pull in the clutch if they were going to tap the rear break for wheel control. Some pro's shift up and feed the clutch on landing with the throttle pined if they're heading down a straight. If they're landing a double or a triple into a corner then no.
Get some help from a buddy before you hurt you're self. If you were jumping fine on a 2 stroke the 426 should be no problem.