You've got a couple of options.
First, you can install a "terminal valve" (twist-on type) from Valterra. Then you can leave the "hard to reach" tank valve open and just dump from the terminal valve. The only "drawback" to doing that (I do it all the time) is winter camping. With the terminal valve, there's water in the exposed pipe, so that would possibly freeze. With spring, summer and fall camping, it's usually not a problem. Here's a link to one place to get the terminal valve.
https://www.amazon.com/Valterra-T58-...y&sr=8-1-fkmr1
The second option is to use the awning rod to "hook the end of the valve handle" and pull it open/push it closed with the awning rod. It can get "tedious" to keep the rod in place on the handle, so for me, using the terminal valve is easier and makes for much fewer "angry verbals"