First trial cut off the miller. 3mm MDF, 4mm/ft scale:
I think this is going to be doable.
I used 3mm MDF for stability on the miller. It would mean packing flexi-track to match the height. I might try 2mm MDF to compare.
Cut wth a 3mm dia. 2-flute slot-drill, gently cleaned up with a Stanley-bladed window scraper, and a light rub with 320 grit sanding block. As usual the camera is cruel, but in the flesh the timbers are a good match for plywood strip. No grain in MDF of course, but some natural texture to the surface, which might take stain rather than paint.
Cutting time was 12 minutes, but still the sockets to do. Plenty of scope in the settings for speeding things up.
The cut depth varies between 0.40 - 0.55 mm (I was aiming for 0.5mm) -- I was warned on the forums that the Z-precision is not too good on these machines (relying on the motor bearings). Which might be a worry for precision machining, but doesn't matter in the least for what we are doing here. The cutter didn't seem to be struggling, so I might go a bit deeper next time, 0.4mm might be difficult to ballast cleanly. A 1.5" mesh ballast stone is 0.5mm at 4mm/ft.
But the timber outline size is good, 4.05 - 4.10 mm wide. The left-most timber above was the final cut, and there is no obvious degradation in the cutter. With my toolmaker hat on I might go for a finishing cut with a sharp 4-flute end mill kept for the purpose, but it all adds time to the job.
I'm not intending to mill the sockets right through, a depth of around 2mm should be enough, and easier on the cutter. But it's helpful not to have a fully blind sealed socket, for adding adhesive from below or pushing out the chairs if necessary. So my plan is to drill a hole through the centres of the sockets. Either manually afterwards, or using the miller as a jig borer first.
Having proved the machine works, there is now a lot of trial and error to find the optimum sizes and materials, including trying plywood and the iron-on hardwood veneer idea.