Rab Alpine, Ascent, or Storm bivy with a thick air pad?

I had an older Ascent (same dimensions as the Storm ). With 3" pad I reckon it would be pushing it. Especially at the feet.
Aren't these bivis designed for climbers? (who I guess prefer a ccf or 1" SI mats due to ease of use)

I really disliked the perimeter zipper design. Unless absolutely static, when unzipped, the head of the floor just slips under you,and the sleeping bag hood or pillow ends up in the dirt (or snow). Even partially zipped means fabric over the face. I sold it and bought a Rain Sierra(ID Bugaboo) to replace it.

I think the Sierra or Andes have more room.