If you find yourself wanting to make more of the time in the tree, you can learn to lower stuff yourself while there is a groundworker. I sometimes need to swing something where the time lapse and communication lapse of calling down what I need can make the situation less predictable. If it lower the limb as it swings, I can watch it closely, and know how much I want the limb lowered, and exactly when.
Yesterday, I was doing removals with a crash landing zone for a bunch of rigged limbs. I was able to stay busy in the tree while the groundman was able to stay busy on the ground. In any time that he had extra, while waiting for a piece to land, he had the opportunity to stretch and catch his breath, far from the landing zone, and we could keep the rope routed away from the landing zone.
On anything that needed to be landed, this same set-up allows him to have the brush to deal with, while not having to bring the rope to the same place as the brush is landing.