Yep that's true...i have the info sheet for them somewhere will dig it out , i do recall it saying something about keeping a minimum of 1 bar in them to stop them getting damaged
Ditto. Lowered on Eibachs and bags still left in. No snags at all. I tow a caravan and have never needed to inflate.Yes you can leave them on and lower the van.
Put eibach 50mm on mine with the airbags still on it sat okay.
I did remove the bags in the end though as one of the bags seemed to have a leak.