@thelaughingman: There will be no cover. So if you plan to carry yours system around I do not recomend to use the 180° flip orientation.
Adding a extra aluminum plate that could be used just for this use-case is not an option. So for me the only option is a covering zone with sloted vent holes that is part of the current panel. It can't be over the complete length because there are zones that you need to access e.g. power supply and mITX 8pin ESP power socket.
But I think we should not focus on this because this read zone will it make harder assembly the case.
@Arboreal: You install the drives from the inside on the plate behind the front panel. So there is no need to remove it.