I think it's OK, but I will consult the board guys day after tomorrow (we have Passower holidays still). You can mail me at
zvi@spondoolies-tech.com if something doesn't work on the SW side. We did some testing with acoustic foam chimney, it is possible and does help with the noise but you really need to know what you are doing because if you do it wrong you can burn your house. We do not encourage it and take no responsibility if something happens, but it is your miner
I am not sure that you will need the fan at the bottom, as long as there is good air flow in front and in back it will suck all the air it needs. The SW should protect the miner from overheating by downscaling voltage and then stopping the miner.
Run them flat, the passive convection won't mean much compared to the airflow from the miners. Also the acoustic foam chimney is a bit of a misnomer, it changes the frequency profile of the noise rather than reducing it (confirmed).