However on approach there should not be the need to add a fistfull of power, just a power adjustment, when the lack of power on one will be noticable, but not dramatic.
I have zero turbine time, but I believe they have a rather different aspect, namely time to spool up from low power to higher power.
The incorrect shut down of the Kegworth professionally flown plane gives weight to the view that, destructive levels of vibration excluded, a shutdown or feathering on approach is inadvisable.
Personally I believe the action to take before feathering a prop should be to throttle back that engine to check you have the correct one.
An error can then be quickly remedied