Print with PETG or other material that is more temperature resistant, at least for the Top piece, since it is hit by the fan exhaust.

In the slicer (Cura), I set Top/Bottom Layers to 0, Infill Multiplier to 2, and Extra Walls to 2. Should let the fan breathe without issue.

4x M3 heatset inserts.
4x M3 x 18-24mm long screws

Rubber feet from Home Depot

This is for the used Datto ALTO 3 V2 that I sell. Should work with ASUS Beebox or Intel NUCs with similar hole pattern and layout.