Could a tandem twin-engine configuration ever have worked

IMO the proposed Do-435 night fighter had the most chance of any Do-335 variant to enter mass production. Aerial performance would be superior to the Ju-88G and every other propeller driven night fighter during the summer of 1945. The Do-335 would be expensive compared to a Ta-152 day fighter but it's probably as cheap or cheaper then the Ju-88G.