After receiving confirmation from Sonex on some baffle issues (basically, it's just baffling - wrangle it however you want to get it to fit the way you want...), I finished the initial fitting trial-and-error process.
Lots of trimming, checking, trimming some more, etc. Main areas of concern were around the right side exhaust flange on the cylinder head and the lower tabs that fit between the cylinders and the SuperTin on both sides.
I had bent the left side per the plans (two 10 deg bends) but this was too much for that side. Because the cylinder pair on that side sits further forward than the right side, the fence now curves more than angular bends. Once the side baffles are installed everything will fit nicely.