There is more than one procedure that includes the RHS set screw. I've done it both ways over these 69,000 miles and find the "defeat" method much simpler and just as reliable.
I do use a jam nut on the white knob and, yes, you must be diligent to keep it from moving the knob as it's tightened.
FWIW, my white knob rotates on threads, making the rod shorter or longer while the right side of the rod stays soundly anchored with its lock nut. I should have read Ratch's post more closely, but I'm understanding his white knob stays "affixed" and his rod length must be adjusted from the right(?). Good news there is you surely wouldn't need a jam nut on the left!