Very very nice. That's got to be the best center pole design I've seen yet. I'm going to have to steal your design and try to make it quite a bit bigger. Do you think a really big one would be sturdy enough with a center pole?
No stealing, the article is meant to inspire others to do the same or improve the design.
I did this one about a year ago, now im doing something similar but smaller and more lightweight (as well as multifuncion). Something I've learnd in the process of making my new design, is that the pizza slices are a bit unnecessary. I did that because you always get fabric in 1,50m by as much as you want (in that case was 10 meters long) and I thought at the time that making this pizza slices look alikes was the best option. Now I would just overlap the fabric and then cut it. something like this:
(EDIT, I did some ascci art here and when publishing it it got broken all the time, sorry, no visual example, will come up with something if you dont understand what i mean by reading.)
Of course this is a very limited example, hope it helps anyways.
The other way is tested and works wonders, but its a lot of work (unless you have a sewing machine) so if you can, try this other method out and let me know how it goes!
About stability, I think that the centerpole and 8 spikes design is very stable. if the fabric can take pressure, you can adjust it very tight and the stuff wont move even on the hardest winds as its quite aerodinamic and the design itself pulls the structure's weight to the ground trough the centerpole (that shit gets really stiff when its properly set up)