Hi Jeremy,
Some comments ...
So far you have a frame and a tyvek sheet draped over it.
That is easy and quick to do, the hard part has not started.
(I can and have done several 'project ideas" like that but cannot do the rest...)
I would estimate that you have maybe 10% of the required work done so far.
For the hard part...
Cuben is a rather difficult laminate to work with (no personal experience except having handled several items made with it)
Not only it is difficult to stitch/tape together you also need to work out the panels to a very exacting degree because there is no stretch in the material.
Going from draping to exact size is not all that simple and very difficult if not impossible without a good CAD programme.
Folds/wrinkles on the finish product means a noisy and less wind/snow resistant shelter.
The tricky bits are details such as vents, air flow , door panel design, pole hubs, pole pockets, zip placement.
As for setting the frame up you do need something to keep it together however that is usually done with a floor such as a tent footprint and best done if pegged down.
see for example

On your lawn it maybe easy enough to attach those poles to that freeflow ribbon , on snow in particular it may not be so.
Anyway something to consider.
Franco