Kept the truck where it was, moved from tree to tree and re-tensioned each time. Worked alright, the trees were within a rough 20' circle of eachother.
Rigged the speedline "above" a set of about 6-8 branches at a time, so that when I cut them they didn't shock load the zipline, just kinda rolled right on off. Clipped a second 7/16" rope to the pulled, i'd make the cut, it'd go zipping down the line. H.O. unclipped it, then i reeled it back in and went again. Sometimes did more than one at a time. Seemed to work smoothly once I managed to find the "rythmn" that I was looking for the first time.
I'd set up the speedline for the next area, he'd roll the truck forward till it was taut, then I'd go from there. Seemed to work pretty easy. I thought it'd be a mess with all the extra rigging but it was really no big deal. Figured out a way to use a rack or figure 8, and another anchor strap as a method for cutting a heavy limb, and *lowering* it till its weight was taken up by the speedline so as not to shock-load it. Good stuff.
In specific situations I'm gonna make speedlining a normal part of how I do things, because I see promise in it.