In reply to Removed UserNangadreams:
I've got a "blow up thing" (a Thermarest Neoair Women's*) that works fine on alpine bivis. Not popped it so far. Just clear away the pointy stuff and there's no issue. It's comfier, warmer, lighter and smaller than anything foam in my experience.
*Why Women's you may ask? Well its the perfect mix between 3/4 and "full" length for me. I'm 178 cm, so once I've got my pillow (bag) at the top it's the perfect length. It's also a bit warmer than the regular version - clearly Thermarest think women are short-ish and feel the cold.
Post edited at 17:57