[LargoLasskhyfv]

That backside is looking rather full. Nothing which a few blocks of styrofoam from packaging residue, maybe some cardboard or other plastics, and adhesive metal tape, and/or some super/hot-glue couldn't easily fill.

Or something 3D-printed...

Or did you mean the height of the ports on the backside itself is too large for 1U already?

[johnklos]

The ports would easily fit in a 1U case, as would everything else, including the fan and heat sink.

The metal back panel is standard. It'd be nice to have one that's made to fit 1U cases.