Re: pretty pictures
The metalwork at the front of the chassis shows 2 full height and one half-height PCIe type cutout. This is the only logical place for them given the fans and PSU's take up the whole back of the chassis
One of the front cut-outs looks like is a drives vs expansion trade-off as is common in small form factor servers.
Given that its an Open Compute machine, I expect that the current Linux builds for Qualcomm processors will run on it - and if not, then I don't expect it will take the OC community long to sort out any bumps in the road.
Agree with the other posts - it makes sense for it to use u-boot as that's well established and reliable.