Also, the description claims a back mounted radiator but the render shows them as front mounted (drenching the modules in hot air). Any clarification from Hashfast as to why the render doesn't match the description, or more importantly, which orientation is the intended design?
Not speaking for hashfast but for rackmount servers airflow always has to be front to back without exception. A datacenter is going to use hot and cold aisles and they aren't going to reverse the flow on an entire row of racks (up to 400 servers) to accommodate a special request.
So either HF would need to put the modules up front or the airflow will be radiator first. My guess is they have no choice but to have radiator up front because 2U is only 3.5" high that probably means the radiator is no more than ~3" tall. A 19" case is ~17.5 wide but putting it in the back means losing 4" of width to the PSU. Not sure a 13" by 3" radiator is up to the task of dumping 750W.
Still your right the photo seems to directly contradict the description.
The airflow is front to back - the push/pull fan configuration moves so much air that the temps in the box are kept reasonable. The coldest air hits the rad first, which is where it's needed to keep the chip temperature low. Also it's not possible to put the rad at the back of the box, since the PSU has to go along the side and reach the back - would mean a narrower rad, with lower capacity.