A-frame needs the pack to not be too wide at the top, so it’ll fit that A. That’s great, nice low center of gravity for skiing down, and 2000 cu in/32 liters should fit fine down there.
I guess with diagonal, it could be a pain hiking up steep sidehills if the angle is the wrong way and drags.
Thick trees (but not low!) or narrow trails favor the A.
I think of A-frame as the heavy-duty alpine way, diagonal as the lighter, more casual look for spring. A-Frame tends to be stable, not shift unexpectedly when you are making some gnarly ice moves in soft snowboard boots. But there is the ski strap weight and the weight of the strap to keep it from just hinging down behind you. That anti-hinger can be a second compression strap towards the top of the pack. Osprey Switch36 has it double as the diagonal ski carry loop.

3.3 lbs ouch.
Nice helmet pocket, how would it work as a nutcracker to crush an ultralight helmet in there. You could say, if your helmet is in your pack while moving, it must be mellow conditions so probly diagonal carry? But I like to have my whole package ready to go into the back of the truck in the morning.
Camp X3 600 is 21 ounces. looks good but only 1830 cu in. They have what they call the XPress system to carry the planks in an X, but I see no pics…….