Having researched the Me 410, the plane with two 8mm and two 20mm it's just an under armed Mosquito. (I know it has the remote controlled side guns).As far as added power of the 50mm's, we have the 262 with great speed and 4 30 mm's. We have the b-29 with all it's fire power. ( oh , where's the atomic bomb)
Just kidding on that. Besides we have planes which are very strong and we have very weak planes. We have four P-40's. why so many ? we have five P-47's. Why so many? If we are to get a new plane, make it different. From what I have read , the Me 410 with the 50 mm Bordkanone only carried a limited number of rounds anyway.