The valve on our I3FW was often hard to turn as well. Partly due to location, objects in the way, etc. I used a piece of 1 ½ ABS 20” long, with notch’s on the one end to slide over handle, grip tape on other to aid in turning. Worked well for me.
Good luck with value what ever you choose to do, hopefully something works for you.
2020 Dynamax Istata 3
Newbie to RVing and looking forward to the experiences and meeting others during the journey