i don't know why you'd pack a bivy like that if indeed, you might only need it for an emergency.

the SOL works better as a ground cloth and can double as a warm, emergency bivy that's a fair bit lighter.

Having spent many nights in bivies in the mountains, on mountain rescue teams or just climbing, you will find a bivy is a damp place to spend the night. particularily if the weather has sent you packing into the bivy in the first place.

No matter the brand or type of laminate, laminate bivies are sog machines in typical "I needed to get into the bivy" conditions.

but to each his own, once it becomes ultralight its just parsing hairs about what needs to be taken anyway. Just hoping you make the right decisions about gear