TH400 valve body mod question

I tore down a 400 trans to build for a friend of a friend that had a shift kit with modifications I haven’t seen before. The spacer plate is plated gold, stamped with the numbers 1400044-03. Other than the modulator to 1-2 accumulator hole being drilled to 3/16, all the other holes are present and normally sized. The big question I have is a exhaust hole has been drilled in the valve body for 3rd clutch exhaust (in the crescent shaped area above the 2-3 accumulator piston). I spent some time looking at the hydraulic chart, it seems to me all this would accomplish is venting line pressure that keeps the front servo released. Am I missing something? The guy swears the trans worked and shifted well, and tear down showed some hard use but nothing severely worn or cooked. Just always trying to learn something new, and this is something I haven’t seen before. Thanks