I thought I would share my experience with this board. I recently bought one off ebay to be used in a 2u NAS I was assembling. I paired it with a SuperMicro CS-825TQ that I also purchased off ebay. This board works very nicely for this purpose, as the front panel header appears to be the same as the X8 board that came with the case so I could just plug that in directly. There is also a header on the board for the power supply monitoring. I am currently using a PWS-920P-1R. The board came with bios password locked, but I was able to use ipmi to reflash with the bios version found here to remove the password. The board came with a steel i/o plate that has screw holes, but I had purchased an Aluminum pop-in plate directly from SuperMicro that I used instead. I purchased several of these, since the shipping was as much as one of the plates, so If anyone needs one I have a couple available for cost + shipping ($12) - sorry USA shipping only.
I installed a SuperMicro SAS2 HBA controller (AOC-S2308L-L8E) and 7 4tb drives in raidz2 (+1 spare), along with a cheap 128Gb ssd for the operating system. The system is running Proxmox with TrueNAS virtualized and all seems to be well so far, although I am thinking about purchasing a 920SQ power supply to reduce the noise. I had no problem passing though the HBA controller, but had to set the ACS option to split the iommu groups in order to pass though only some of the 10Gb ports.