There are situations where you want both hands on the paddle shaft, e.g. when kneeling, or during fast transitions, when you don't even have time to reach for a proper grip. Coming from kayaking, I instinctively always use a kayak paddling grip, i.e. with both hand palms facing down, as I feel this gives me much better control and makes it easy to transfer the power to the blade.
Yet I see many people, not only beginners, who have the palm of their top hand facing up. This is probably a natural thing to do when climbing a pole, but I doubt if this makes sense with a SUP paddle. I find it really hard to control the paddle this way, and it feels weird on the upper wrist when trying to put power on the blade. The only reason I can think of is that a SUP paddle is typically more vertical (sometimes even past vertical) than a kayak paddle, although that doesn't really make a difference when kneeling.
What do you think? Are their other reasons to use that pole climbing grip that I didn't think of? Are these just my old kayaking habits, which don't make any sense on a SUP?