Your still overthinking this job...
provided the seat angle is different (and of course reasonably concentric) to the nipple it will seal. See diagram below.
there needs to be a knife edge sealing area between the nipple and the seat. If the angles are the same, unless you can lap them together it will leak.
A standard sharpened drill at a conventional angle will do the job absolutely fine. A drill sharpened at a similar angle to the nipple sealing face will very likely leak. Ideally you’d use a flat bottomed drill to finish but it’s not essential. and don’t forget the material of the callipers is softer than the bleed nipple, so some deformation will occur and assist in sealing
provided the seat angle is different (and of course reasonably concentric) to the nipple it will seal. See diagram below.
there needs to be a knife edge sealing area between the nipple and the seat. If the angles are the same, unless you can lap them together it will leak.
A standard sharpened drill at a conventional angle will do the job absolutely fine. A drill sharpened at a similar angle to the nipple sealing face will very likely leak. Ideally you’d use a flat bottomed drill to finish but it’s not essential. and don’t forget the material of the callipers is softer than the bleed nipple, so some deformation will occur and assist in sealing