What does the push/pull get you over a more normal configuration?
Pros:
- Less drag
- More benign engine-out performance (no asymmetric thrust)
Cons:
- All of the normal pusher prop issues - cooling the rear engine, harder bail outs, more dangerous crash landings, less efficient propulsion (rear prop is getting thoroughly disturbed air), engine accessibility issues, pitch/take off limits to avoid prop strikes
- Fuel feeds need to run both fore and aft
- Potential center-of-gravity or airframe structure issues since you've got heavy items at both ends with your lift in the middle
- Engines are going to limit where you can place control surfaces and how you connect the flight controls to them
- One of the usual benefits of twin-engine prop planes is that it frees up the nose for radar or a heavy armament or both, and potentially room in the rear for a big fuel tank. The push/pull layout kinda gets in the way of that
There's a reason it's such an uncommon configuration. But we do have the Cessna 337 Skymaster.
https://www.youtube.com/watch?v=epGK08BD5lE