I agree that an MEH with a low end cut off only extending to 300 or 400hz makes little sense.
Your K402 based MEH look to be astounding, but the 402 is really wide for a lot of rooms, especially if used LCR. And, it exactly cheap either.😊
The sweet spot for me would be an MEH using a 2” driver crossed around 400 to dual 12” (or 8”?) woofers mounted on the sides firing through the horn. Low end cut off of around 80-100hz. Preferably 24-30” wide.
Perhaps this is pie in the sky.
Maybe the better solution is the Peavey FH-1 + 2 Large Heils from your other thread.