I have a flat alum dash. If you run the wraparound dash it allows more room to mount it in the cockpit. With the flat dash it is fairly close to your hands. I do agree that mounting it on the engine side is much simpler with not having to run the wires thru the dash but you do have the possibility of heat soak to the box. Damned if you do and damned if you don't I guess.

I have a brand new flat carbon fiber one for sale

Dang I just finished building a new one out of aluminum. With the WAR Series weight rule I still need to add weight though. Your setup looks strong. I'd rather mount it like that but I think it's just to close to the wheel.