I've got a 2400G and have designed a very small form factor case specifically to house a Gigabyte AB350N Gaming WiFi ITX motherboard. It's so small the CPU fan and shroud will protrude through the top and will double as a case fan. I am just getting my new 3D printer setup and hope to print this thing this weekend. It's 195mm by 190mm by 60mm high, plus rubber feet to provide clearance for the vents which are on the bottom. It will be reasonably easy to relocate the CPU fan hole for different boards - it's position is 2 parameters in CAD. I'll try to post pics and CAD files someplace when the design is fully printed and finalized. Or perhaps make it available on Shapeways? There is opportunity to shrink it more in the future, but I went for 30mm radius curves on the front and haven't shaved every mm off the height.
Running Fedora Rawhide, there are some issues still but it's amazing when it boots properly. Plays Video on my 4K TV while barely making a sound or heating up.