I just got my 43 asc’s. very nice. maybe i am too lean, but for me they do not contact my forarm at all really. My hot take is that maybe if my forarms were a couple of inches longer (pads further back) i would have better contact. the forarm section seems to be designed to work with pads that are flush with the top of the extension bars clamping area.
note: right now i am using the felt dagger stem/pd svete bar/bayonet mounts/brackets, and the original profile design race armrests (5mm pads i believe).
The 43 asc’s have a shorter clamping range, so to get them as short as i want, i need a combined base-bar/extension clamp solution (supersonic). i may upgrade to the race+pads while i am at it.
the ergonomics of the bars make me think they were designed for someone with narrow hands, long forarms, or a very very low pad setup. or they were never designed to support once you get below the wrist.