Is that solely for taxi purposes?
What happens if you are at full (master) throttle and pull the fuel condition lever to idle?
Nothing!!!
Fuel condition lever can only bump up to the 70% gas generator speed. If the power lever is set to a position that is greater than the high idle selected it will simply pick up on the fuel control linkage and increase gas generator speed from that point.
If the fuel condition lever is in low idles - retarding the power lever to flight idle will give you a low idle condition.
If the fuel condition lever is selected to the high position then the power lever will bring the idle speed down to high idle when retarded to the flight idle position.
Mx Trainer