Looks like this is built for vintage racing.
Only 400 Nm? No forced induction, then. Also, yes, straight-cut could be extremely loud. There also does not appear to be any provision for a speedo drive. The shifter surround looks nice, though, and is fully stabilized. Since it's a H-pattern, I wonder if that could be applied to the existing box? The parts they laid out doesn't seem to include a rear casing, so it might be compatible.
I bet many of us with a 265 would welcome the opportunity to jump to a 6 speed to increase the gear spread (to improve off the line performance) and bump the final OD ratio a touch. (perhaps 0.6/0.7) With the available ratios on their website, that's not what this box is for. It would also be really nice to have parts availability to rebuild the box again, most people I talk with won't touch it.
So, switch to helical mesh, add or keep a speedo drive, change up the ratios, and I'll be on board. (basically make it a road box)