If Fibraplex could change the angle on your alloy elbows for carbon poles, they could probably provide Aaron with whatever angle he wants. He might have to buy some poles from them, though. Hope the rumor about them increasing the strength of their poles is correct.
Now I will go to Roger's site and see if there is any new info about making elbows. When I made some 3/16" ones from Titanium tent pegs last year, it was painstaking. Don't try it in a cold room or with a short radius rod bender - snap!
Aaron - Just a quick session with a protractor and some graph paper suggests to me that a 145 degree angle would be AOK for building a tent with Roger's design. Just sketching the three angled pole out on graph paper makes it look like there will be too much spread of the poles toward the tent bottom; but that is OK, because you are going to bring the bottoms tips of the pole together, flexing and arching the whole assembly. That creates tension to keep the floor spread taut, and just right for enough angle to both the upper and lower walls to shed rain and snow, with lots of shoulder space. Am wondering if you are reading 145 degrees to be 45 degrees, or perhaps are not considering that the pole assembly will be flexed.
[Edited to remove application of Quest .340" O.D. elbows that will not work].
There is an application for the Quest .340" O.D. elbows that might work well for you; in that the ferrules on these elbows fit well into the Easton Carbon FX pole sections that one poster PM'd me are now available from poleforyou in smaller than wholesale quantities. The FX weigh a little under 12 grains per running inch, compared to the 8-9 grains of the arrow shaft sized carbon poles. But the FX are quite a bit stronger, and will make your tent sturdier. The only downside would be the long length of the Quest elbows, since they include ferrules at both ends, so would be a little more unwieldy to disassemble and fold up than poles with shorter elbows. The Easton elbows from Quest are really well tempered also, and will hold the angle upon which the tent structure depends.
The Fibraplex elbows are sized for carbon tubes, but if they fit over the tube as stated above, would be too small to fit some larger shafts, Victory 300 for example.
So, for them you would probably have to use the Fibraplex shafts, for which the elbows are made. It would be worth it if you could find some slightly thicker walled shafts the same diameter as the Fibraplex, because additional layers of the wrapped carbon will improve the strength of the poles.
The great thing about tubular elbows, as opposed to solid rod ones, is that you can shock cord the whole pole together, which would be much easier to contend with in Roger's design. The pole set does not fold completely flat, as it would without elbows, but folks have been putting up with that for a long time with elbowed poles on tents. The design I was working with using solid rod Ti elbows was much different - just one elbow connection at each of two tent apexes, and nothing like what you are considering, so maybe my comments about making solid elbows were not apropos.
I'm sure Roger and his site will provide you with lots of help if you are going to make a tent with his design. That improves your chances of success way more than striking off on your own. I have a basement full of failed creations that support that observation.