I think I may have a solution, or at least part of one. Maybe it came from a comment I saw on RCU at some point. The idea is to slip the end of a 1" segment of heavy duty fuel tubing over the end of the needle valve. I tried just twisting a long length of tubing but it twists too much. But when I shorten it to a 1" segment and then insert a brass tube in the other end so that there's only about a 1/4" gap in the tubing between the brass and the needle valve, turning the brass tube turns the needle valve fairly easily. And it turns it from almost any angle.

The idea still needs some refinement, but it's a start.