I'm still trying to figure out the mounting of the NUC. I could build a shelf but that puts all the weight on the bottom plate and I would prefer something that keeps the NUC isolated from the bottom plate. I originally planned on something from the heatsink parts but they don't line up with where I have the NUC. I may move it to the center more and extent the heatsink replacement parts to get around the "bump" so I can add some 3mm bolts to mount the NUC.
Additionally I ran into another issue. Since I am using a 3D printed bottom panel. There is nothing holding the panel at the corners which allows flex on the NUC end. You can see it on the left side of the following pic.
My current plan to counter this is to remove the pins at the corners of the bottom plate and build a method of securing at the base of the 4 corner support beams of the cube chassis. I've modeled a couple of ways to do this but I'm not sure which direction I will go with it yet.