I tried using a muslin to cover dd1 when she was feeding in a restaurant, at their incredibly rude, cover or get out request. Prior to the cover, dd1 had been feeding quietly and no one seemed to have clocked that I was feeding her and not cuddling her, apart from our waiter presumably.
After being covered by the muslin dd1 got far too hot, started thrashing around, wrenching off and screaming. We ended up leaving the restaurant before our food arrived, me in tears, and the manager being berated for being a "baby-hater"
by a lady who was sitting next to us and saw the whole thing.
We never went back, but the funny thing is I see them now in the the local paper advertising themselves as being bfing friendly
among other things. I can't help but be cynical about that.