The original plan to CNC mill the dovetail seems a no-go. The tolerance is ±0.05mm, which is way too much to maintain a decent sliding fit at that small size. At LMC, parts may even disengage and fall apart. Sliding fit tolerances for a Ø3mm hole are in the range of ±0.02mm.
Is it possible to reach these tolerances with a CNC mill? It is a high-volume production part, so they are not in a hurry to do something more exotic. But, it seems we need something better.