It would he the 3D printed corners which would rest on the desk if I went this route. The 3D printed material is not as hard as Acrylic so it won't cause scratches as easily, but it is still something to consider. The 3D printed material has a slight grainy textured surface finish.
The 3 possible options are:
1) lowest cost - design feet into 3D printed corner sections.
2) medium cost - source high quality stick on rubber feet
3) highest cost - screw on style feet with rubber grip base
I know some of you may be thinking what is an extra few quid (£) difference going to make, but it's all these small decisions that stack up and will push the case price above what is being targeted.
However, it could be offered as an upgrade perhaps.
Yes it makes sense that vents in thicker materials will increase fan noise further when the fan is placed against them. It isn't something that I tested.
The plan is to try and avoid intake fans passing through vents, but instead pulling though dust covers or fan guards. The vents will be used as exhaust areas.
The PSU intake will be facing upwards which will require a vent above it, but if you are clever with your component Choice (e.g. corsair SF450) then the fan doesn't spin unless under quite a high load.
Customisation of the acrylic panels will be the most difficult part to achieve, this is because volume does affect laser cutting price when using external manufacturers which is the current plan.
The only way I can see this would be possible is to buy a laser cutter and do the cutting myself, this would allow for a more options without raising the price too much away from the standard configuration/design.
Buying a laser cutter would probably need to be done through some kind of Kickstarter campaign with the initial case run.
