I'm not sure if this has already been touched upon but,
EPR is an indicator of actual thrust.
An EPR of say 1.15 is associated with XX,000lbs of thrust at sea level and at the same FL200.
However, an N1 fan speed of say 60% will correspond to a higher actual thrust value at sea level than at FL200.
That being said as a pilot you want to be able to be able set a thrust lever angle that gives you the thrust you need to maintain your required speed alt etc.
N1 gauges are easier to use but the EPR is more accurate.
I wonder if anyone has ever considered setting the EPR as a function of its scale and not the number.
Say EPR needles at 9 o'clock to reduce from high speed.
Or say 10 oclock for flap full MLW VAPP ETC.
nyone with me?