Need help reporting Taper/foot of a Cone

Respectfully, i feel that note is not a feature of size controlled to the block tolerance.

No matter how you slice or dice a ~1.5" long axis line... Multiplying or compounding 1/10th of the measured value, to equate to a repeatable result that will discern a ±0.010 tolerance is an impossible ask.  You are multiplying your uncertainty of cone angle to equivalate it to that 1.5" along a 12" ratio.  Cone angle is very difficult to control on a cmm.

The engineer either needs to change the spec to tolerance it as an angle form centerline as you are doing ± a relevant angular allowance or go back to school.

Another consideration, the print has that "Bore diameter | Tapered +0.002/-0.000" 
--Is that the intended "TAPERED" cone tolerance?  

If so, construct a 1.5" taper along a 12" line angle, at the nominal bore diameter (consider it as a BASIC value).  measure t values from that line.  Tolerance the t-values as +0.001 / -0.000 (radius of the diametrical tol) repeat radially like 4 times about a few spots down the tapered bore

I can tell you have quite a bit of experience with this sort of thing, and what you say about multiplying the uncertainty along a short length makes sense, so my question for you is would you reject these for the taper measuring 1.530"/foot? That is what the measured angle works out to. I am quite confident in this result, I have checked several parts and checked the same part multiple times and get anywhere from 1.527/foot to 1.531/foot.

In my experience, when I'm uncertain with what the machine is spitting out, I do a "sanity check" on a surface plate with a sine block and an indicator.

That way you can say with absolute confidence, what the demon is telling you, is in the ballpark.  Plus, you can keep product moving at the same time.

the time/effort you need to invest into extrapolating that dimension on the CMM might be more than just checking it the good ol' fashioned way.

In my experience, when I'm uncertain with what the machine is spitting out, I do a "sanity check" on a surface plate with a sine block and an indicator.

That way you can say with absolute confidence, what the demon is telling you, is in the ballpark.  Plus, you can keep product moving at the same time.

the time/effort you need to invest into extrapolating that dimension on the CMM might be more than just checking it the good ol' fashioned way.