Hi TC
No problem with T/R thrust at reduced T/R RPM - there's no major torque to counter - and the flare/level/lever part won't vary the gearbox drag all that much (not significant) - the reduced effectiveness of the T/R will easily be enough... (especially not a problem in manoeuvering turns on the way down - any kind of airspeed (30kts +) will keep that tail near the back - only tiny T/R thrust to stay in balance if you really want to...)
T/R thrust is just about proportional to T/R RPM squared - so 50% RRPM implies 25% of max thrust available - easily enough.
If you think about a running engine off landing you do need much larger T/R pedal inputs to make T/R thrust changes...
The interesting points in this thread is how many people think cutting the throttle is the answer to achieve reduced torque on loss of tail rotor. (as opposed to putting the lever down - Brazilian Squirrel)
AND
The greatest danger when teaching T/R loss is that the student has afterwards an increased chance of mis-diagnosing a tail rotor failure when really they were just caught out by the wind etc