This is an idea I was kicking around for a mid to late WWII Allied era heavy/ fighter-ground attack aircraft. Part of the exercise was to develop a twin engine aircraft that reduces the issue of asymmetrical thrust in an engine out scenario, and reduces the cross section to make it a smaller target to groundfire and improved aerodynamics. One way is to put both engines on the centerline in a fashion like the Dornier 335.

Of course this does create its own problems which like Dornier 335 have to be accounted for. The biggest problem is you must provide some means of escape for the pilot. Just popping up the canopy and bailing out the side won't work; unless the pilot suddenly has an urge to pursue a new career as chunky salsa! You could try the trick of having an explosive charge that blows the back prop off , but that might not always work and the pilot still has to get out of the plane. The answer is an ejection seat which what Dornier decided on for the 335. Besides as speeds had increased throughout WWII it was becoming more an more apparent to designers that escaping from their aircraft was becoming almost impossible to do.

Also one must be certain that the rear prop does not start ingesting spent shell cases or blast exhaust from rocket launching under the wing. Also you would want to make certain that any centerline drop tanks or bombs don't bang the prop when you release it. Perhaps a compressed air system that pushes the shackles down quickly from the aircraft then release the tank or bomb. Kind of like some rail launchers do for AAMs on jets.