I used Nobul for a sleeping bag lining, which is similar, but it seems fairly flimsy. I have some M50 but haven't used it yet and it seems similar. I think you need to baby these lightweight fabrics.
My experience as a Boyscout is that they do not baby gear, just the opposite, but maybe your group is different.
Maybe 1.1 oz is better. Cheap stuff from backwoodsdaydreamer.com.
Down for Boy Scouts? Seems like they might not be careful enough to keep it from getting wet? Synthetic better?