As I have now replaced my test GPU with one requiring additional PCIe power, I have a better working system to test builds with.
First, the bad news- there are a couple of measurement inaccuracies that were made more apparent when I have installed the motherboard and GPU. They're as follows:
- Only motherboards with bare thin metal I/O shields could line up flush with the standoffs. Spongy/thick I/O shields with extra padding will make it almost impossible to line them up. You'd have to go without an I/O shield to install those boards.
- A 20cm PCIe riser cable is just too short to properly align and connect with the motherboard. This can be corrected either by raising the GPU mounting points by >5mm or by using a longer PCIe riser cable (24-25cm is ideal).
- For some reason I have the slot too small where the top of GPU bracket slides into, compared to the very first case I made. The GPU required extra force to push into place, scratching one side of the motherboard tray.
- GPU I/O slot is too narrow for certain video cables. Plugs for HDMI and DisplayPort could be too thick to connect properly, so you may need a thin cable such as this one.
These issues will make installation more difficult than expected, depending on your parts configuration.
Now for the good news- PSU installation is mostly flawless and as expected, and only two cases have been made with these inaccuracies.
The laser cutting shop fortunately uses very low price minimums for orders so not many cases were wasted. They are still usable, but will be more constrained on what parts you can use. The current design I have right now corrects the problems mentioned above. Motherboard mounting is shifted 1mm, GPU is raised by 5mm so you can still use 20cm riser cables, and GPU bracket slots are all enlarged overall.
The exterior volume of the cases remains unchanged. This is another good thing- the dimensions of the case are the same so I can use the same outer panels for the revised cases as the old ones.