I'm new to gear making, but i think a hammock sock is within my current abilities.

I'd like to add a few degrees to the comfort zone of my current setup, I think most of my heat loss at this point is due to the unpredictable wind, and near constant rain. I'd like to keep the design close to the envelope/burrito bivvy style for use as a go-to-ground backup, but that may need to be sacrificed for hammocking comfort.

First i'd like to make the sock out of Tyvek because that's what I already have in bulk, and honestly the first prototype is going to be most useful as a teaching experience.
Could I enhance its breathability with small perforations on the lower half and end venting, or should i just plan the layout around a section of lightweight nylon to provide additional permeability?

Any advice for working around the tieouts of my blackbird, or should i ignore them on the initial prototype in favor of modification after the build?

Last of all, should the sock be suspended on its own ridgeline to keep airspace between my hammock? will the difference even be noticeable?

Please kindly lend me the benefit of your experience.

-Mitch