The only difficulty is seeing behind on the road. I use a helmet mounted mirror but it's not the perfect solution.
On the Red Baron I use an idea lobachevskied from Wendy OTP: B&M Cyclestar mirrors (the smaller ones, with the long curved arm) mounted inboard of the brake levers (with bonus cable tie securing the arm to the brake cable where they cross, for extra stability), with the arm almost horizontal to position the mirror somewhere above my hand. This gives me a view backward over my shoulder, without adding extra width to the bars the way a bar-end mounted mirror would.
On the road one mirror is sufficient. I added a second for BHPC races.
I know the bars on the Fujin are a bit narrower than the ones on the Baron, but it would probably work okay.
ETA: Crosspost with Lightning Phil. We appear to be on the same page.