Of course you can climb on aero wheels, they just aren’t well suited to the task. It will be faster to use a lighter set (W/kg is king on the climbs); unless you’re fast. Then there’s a sweet spot (probably around 45-50mm). The real question should be “can you safely descend on aero wheels?”. Because when you’re screaming down the side of a mountain at 40-50mph, turn a corner, and get hit by a vicious cross wind, you’ll be glad you’re not on a set of 65s. It’s bad enough on a 30-35mm wheel (or at least that’s my experience). There was a time when I was daring on descents. Now I just want to enjoy it without hitting the ground.