I have better range of movement in my right shoulder, and normally I can do the valve drill fine. But pre drysuit, when I'd have my 3mm and all my insulators on, the V drill could be a challenge. I could reach the manifold but not with enough wrist dexterity to quickly close the isolator. I would grab the manifold with my left hand and pull the rig up higher and probably also create a bigger arch in my back. Then I could operate the valves comfortably. If you can get close, it might be close enough.