IF you don't come up with a better method, at least get a chainsaw
extender so that you are further away from the spray.
Goats, by the way (I used to raise them), will eat the leaves and softer
stems, not the woody vines. If the leaves are hard to reach, they may
not bother, but if they do, the trampling of the vines also helps.
They may chew on the bark of the vines--that part I can't remember.
They did like the bark of some trees, but I don't remember whether they
liked poison oak bark. (It was thirty years ago)
Guidelines for judging others:
Click to see the full signature.