The issue with a 5-channel Purifi amp is the actual power supply/wattage.
For the 1ET400A, you’re talking about being able to handle 400watts/channel or 450 watts at 2ohms. That’s over 2000 watts. That exceeds the safe current limit for a 20 amp line with a 5-20P plug (most home electrical lines are 15 amp rated with a 5-15P). Just because the amplifier is light doesn’t mean it doesn’t require juice. Your circuit breakers would trip if you were approaching the limits (which is highly likely as you would be needing to drive five speakers to ear-bleeding levels). From a practical perspective, you can connect three 1ET400A to a Hypex SMPS 1200A400 so it is cost effective to do a two channel or three channel amplifier with amplifier modules connected to a single switch mode power supply unit and not worrying about whether you draw more than 15 amps.
This is also the reason why the reason why the 1ET7040SA comes only as a monoblock. It can supply 950 watts at 2 ohms! The 15 amp home line won’t handle 1900 watts safely (not that you would ever draw that much and bust your eardrums… you’d probably blow your speakers first).
If Buckeye wants to design a multi-channel speaker two separate power connections designed for two separate 20 amp lines……. This is not a practical solution.