Accurate hole location on 1.5mm holes at 25mm of depth

Recently been asked to quote on a job that'll be used to calibrate some pretty high end ultrasonic Gear. Basically there's a series of different 25mm thick plates hardened to about 28 HRC that need multiple 1.5mm holes drilled all the way through. The drawings came without tolerances and when I asked the engineer he wanted them within 0.02mm of each other which seemed pretty vague. I have access to a brand new BM-63VE that a good friend of mine owns which I'd prefer using as I don't trust the wear in either of my mills for this job. Has anyone had any luck with similar jobs? I don't even know what to quote but I've offered to drill a sample before I give an accurate quote. I feel like this job has been turned down by a few other people before me, breaking a drill is apparently not an option either.

What's the tolerance on the hole? Nothing stopping you from drilling undersize and either plunging with a 1/16 carbide endmill or coming back with an onsize carbide drill.

they didn't specify a tolerance for the hole but 1.5mm is apparently the ASME standard for what ever it is they're calibrating.
one of the engineers is dropping around a sample tomorrow so I can talk it over then. As to carbide I'm limited to about 3500RPM and my smallest ER collet is a 1mm-2mm, I was hoping to get away with spotting and using a HSS-Co drill. Is there even a carbide end mill that'll safely give me 25mm of depth?

Off the shelf? Harvey will have something, personally I'd relieve a regular length in house. I would imagine double drilling the hole should get you fairly close barring any mechanical issues with the machine.

0,02mm tolerance on exit side with 17:1 ratio hole dimensions? Sounds like gun drilling job to me.
(Just a home shop hack here and I'm happy to be proven wrong)

Edit: and if the tolerance is relative to other holes you need to get the invidual hole positions to +-0,01mm.
Even just measuring the hole locations could be interesting.

Found out there was just a degree of miscommunication between the engineers and the tolerance was "0.2mm" which might as well have been a sausage down a hallway. 2500rpm or so peck drilling with trefolex and no coolant, actually drilled quite nicely.

Difficult, get pressure or speed wrong and they wander, even titex solid carbide, is getting it EDM cut possible?, at least it will come out where you expect!, I had moderate success drilling a plug with the hole in a collet and shrink fitting on one occasion (I think it was less than 1.5mm, the plug was 6mm rod)
I drilled and reamed the 5.88 I think or 5.95 thereabouts on the mill and heated the part, nitrogen dipped the plug and dropped it in, it's still there I beleive.
Mark