I almost never use a haul-back or pulley. Rather than straight down lowering, and the back and forth between ground crew and climber with straight down lowering, I'd much rather speedline it closer to the chipper, butts pointed the same way, tensioning for a whorl at a time, popping them 1,2,3,4,5,6.
Get lots of slings, and connect two slings to one biner, as possible. it goes faster that way. When they get a dozen slings, they can attach to the climb line, then you pull up when you're ready.
It can go slow as molasses, if you let it.
I can speedline stuff on my own, tensioning it myself, keeping the groundies moving on unhooking and processing.
I differentiate them as controlled speedline and uncontrolled speedline (rigging line or not rigging line). I mostly "zipline" stuff, as you're calling it, Benn.