1st suggestion:
If able to access easily, reposition the valve. It's held on by 4 bolts and nuts.
2nd:
You could replace it with a Cable Actuated Valve
Remove to factory installed vale, install the remote actuated valve at a different angle(90° from original position).
3rd
RV plumbing is standard ABS. Replace the valve(by cutting the fitting flanges off) and fitting with a 3" ABS coupler.