Without the pipe attached, you can hear the occasional miss fire, and when you put the pipe back on it picked up rpm and cleaned up... It almost runs as if it were running on glow plug ign.
There's no overlap persay between the induction / exhaust ports on a rotary engine, but the increase in scavenging on exhaust from the length of straight pipe clears any residual spent gases, and in turn improves induction fill.
Certainly would work well as a pusher... see what you can come up with in terms of a custom pipe of sorts with a small expansion chamber off the exhaust port, and extend the pipe in a gentle return aft.