grsychckn, an inquiry on revision 5: how much clearance is there from the rear motherboard to the case's bottom when laid flat?
I'm still vested in looking for M.2 SSD thermal pads/coolers that can be used for the rear M.2 SSD between the gaps.
I'm hoping I can use
Gelid's Subzero M.2 Cooling Kit, or
Silverstone's STT-TP01 Thermal Pad.
Also, for reference, I'm planning on getting MSI's B360I ITX mobo.
Here's a picture of its rear.
All that said, can it be done??
It can be done. I'm going to give some measurements I've taken from revision 4 prototype as revision 5 needed to be shipped back to the fabricator so they can confirm my adjustments for the front USB panel fitment.
Rear of mainboard to inside of side panel: 10.7mm (.421")
Measurements with Installed components
I'm using an ASROCK X350 fatality with a Toshiba 512GB m.2 (single sided) in my prototype and I'm quite sure the following measurements will be very similar to yours.
From memory chip surface to inside of side panel: 6.35mm +/- 0.05mm (0.25")
Note: I've had to enlarge the back side cutout to accomodate clearance for some m.2 locations. I initially based my hole on an optional corsair mITX conversion kit so I assume it to be standard (and maybe it was at the time). Regardless, the back panel hole has been opened up by 0.283" more to give more clearance for m.2 drives located in this position. I could see this potentially being a problem with some motherboards as the m.2 location is not standard. If there is a clearance problem with your m.2, the following measurement is what you should use:
From memory chip surface to inside of main case: 4.98mm +/- 0.05mm (0.196")
Based on these numbers and the fact that my 5mm thermal pad I purchased is not thick enough to contact the side panel, I would feel safe saying anything with a total thickness of 6mm or less will fit inside the case no problem. I wanted to have the memory chips contact the side panel because it is such a large surface area I believe one could get much better cooling from that than adding a heatsink but I don't have time to run these tests right now. I'm focused on getting supplies and reading my garage for the laser cutter that will arrive in a few weeks.
Because most of the m.2 heatsinks *seem* to be around 3mm in thickness with included 2mm thermal pad, they should all fit assuming your m.2 has clearance through the cutout on the back of the case.