OK, after almost finishing the tarp(should I make it a poncho or a cape??), I decided to go ahead and make the bivy sack to go with it and a new stake bag out of the envelope the materials came in.
The Bivy Sack weighs 5.27 oz, which is lighter than the Vapr Half zip.
There are seven tieouts on the bivy for various purposes- 1 at the foot, and 2 on the corners of the foot pocket, 2 at the head of the bivy, and 1 each on the opposing faces of the head flap.
Above you can see the tieouts at the head of the bivy.
View from the side demonstrates bathtub bottom and closure system of head flap.
Cordlocks used to cinch down opening in bad weather, view of zipper, and head flap overlap of body portion.
Carabiner clips the head flap and body portion together, and the bivy zipper can still be fully opened with a propstick in position.
Note that for the stake sack I sewed a loop onto the bottom for the purpose of attaching carabiners/guylines I use for quick setup. The stake sack is closed by tucking in the flap of extra material into the opening.