Not the case in the 747-400/-8. There is a distinct change in the force required around the 9-10 degree range. The tail moving into ground effect is the cause.
Proper technique is to rotate at 2.5deg/sec with no pause to target 12.5 deg. initial (which is tail strike territory). However, executed properly this ensure about 18 inches of tail clearance at max weights prior to liftoff. A two stage rotation is not required to protect the tail. Mostly, on the 747 at least, if you see it it's just poor technique.
Of course, none of this precludes the PF from adjusting rotation rates and pitch attitudes for the given conditions (W/S, gusty conditions, eng failure, etc).