Ah, if it was only that simple.
If you dig DEEPLY into the way of SOME installations, you will find the answers you are looking for.
It would be a waste to have the full 12 bit recorded accuracy used over the whole range of the ind, leading to less RECORDED accuracy at lower RPM's etc.
Of course the S76C+ uses ARINC 429 data and these figures are better than 12 bit, but still have errors when converted to 12 bit for the FDR, and IF you use FDR data for PA calc, that would be a problem.
Another problem is that EuroCAE ED55 recording params spec states the max reading to be recorded, for instance this is not the Max N1 of the eng e.g. 101.2% N1, it will be a lot higher like 120% etc, making the scale even less accuratley recorded.
Well, this thread has left the tracks and gone off into the deep and dark gloomy world of sadness...