I went ahead and moved the prussics over onto my whoopie slings, but I don't really use them.

I've found it's easier to just attach cordage and Fig 9s to either end of the tarp and adjust/tension it directly to the trees on either end.

You can adjust the height of the tarp above the hammock much easier that way, and it's simpler to skin the tarp seperately from the hammock that way, keeping the hammock drier when you've got a wet tarp.