Regarding the Minimum NPTH Diameter

The JLCPCB capabilities page says a NPTH (non-plated through hole) must have a diameter > 0.5mm.

However, the drill sizes are from 0.15mm and up.

On a multi-layer design, I understand any non-plated through holes are drilled after all the etching / vias / electroplating is done.

Is that understanding correct?

Does this mean the drills used for the NPTH step are different from the drills used for drilling the vias / etc?

If the drills are the same, I assume it should be possible to have a 0.3mm NPTH?

Could you clarify for me?

Thanks!