After a lot of internal debate and staring at the bike, I decided to scrap the idea of making fender struts and/or a sissy bar from round bar. I decided to make a fender brace from flat stock instead. There are lots of pros and cons to each.
After my initial attempt failed (too narrow), my 2nd try at bending 1/4" x 1" x 3-foot piece flat stock to match the inside of the fender was a success.
Then I made a template from much thinner flat stock to figure out the bends to clear the tire, brake rotor, and pulley. The thinner material allowed me to find the correct the bends easily through trial and error and not have to heat the metal to bend it.
Then I heated the 1/4" stock with my MAPP torch until it was glowing red and bent it in my vise to match the template I made. One trick I used (which I do not recommend as it's probably not exactly safe) is to warm the bottle of MAPP gas to room temperature before use. I set the bottle on top of an electric heather to do this, rotating it regularly and not letting it get hot. I swear it works so much better versus when the bottle's cold.
Careful measurements and scribing the metal to know exactly where to clamp it were the keys to bending the fender brace correctly.