For all the effort, all the time, the tent is not usable.
Apparently, the canvas is not really cotton. Applying a waterproofing product for cotton to non-cotton canvas results in a smelly, never-drying disaster.
Fortunately, I only waterproofed the roof. The walls are ok. I'll just have to make a new roof.
That won't happen in time for Estrella, so I guess I'll be using my First-Up pop-up as a tent one more time.
The disappointment is really, really intense. My elbow is hurting from the abuse of sewing that thing, and now I can't even use it.