Automatic feedrate override

[hunserv]

I am working on a servo project (very slowly) and wondered, if an additional feature could be realised:

By feeding back MACH the servo loads of each axis, a feedrate override could be utilised, if any of the axis load goes beyond a certain percentage...
Now could someone tell me how to realize this feedback? e.g. modbus analog inputs? (no high resolution is needed) or even a digital input would be OK, saying any of axes are above x% load, so override feedrate by y%.... or something like that...

This way even steppers could be made unstallable (encoder feedback, and PID control on servo - this would work only with high-rate microstepping, the "stepper-servo" is quite nicely working, but of course similar control is needed as for DC servos)