Ken,
For seam strength, we analyzed the seams and determined which were the most vulnerable to stress. These seams are both taped and stitched. The rest of the seams are simply sewn.
As to the best method of seamsealing, I don't have a definitive answer. Silicone will simply peel off cuben fiber when dry, so it's not a good candidate. Though you could use silicone on the two pull outs on either side of the tent. I've been told that SeamGrip should work, but haven't had time to try it. When get around to testing, I'll report the results.
The good news is that the design of the Refuge X minimizes the possibilities of water penetrating the canopy and into the tent.
Ron,