The only time I've run into this being an 'issue' is setting metronome BPM coupled with note value in my DAW software / using pre-recorded drum loops / and setting the correct numerator/denominator.

With my current DAW, I have to be within 20% or so of the correct BPM in order for the time stretching/compression to sound decent - might even be less than that, I've never done the math.

I will tap tempo in either correctly or 100% off, which one finds out pretty danged quick!

-Scott