Many of TC's EOLs, like mine, will have been in a Gazelle where you enter auto and, when sure of making the landing area, retard the throttle to ground idle.
It is an EOL in that there is no assistance possible from the engine, since we were actively discouraged from advancing the throttle again in case of surge or damage to the clutch ( have done it once though to avoid a mid air).
Back to the drag issue - I don't know what sort of freewheel arrangement the 300 has, I assume it has some sort of centrifugal clutch/ramp and roller gizmo that does the job.
With the engine running, but at idle, there is a small rotational speed difference between driving and driven parts so drag will be minimal - with the engine stopped there will maximum speed differential so there must be more friction and drag. Engine ancillaries (pumps, generators, alternators etc) may also contribute to the 'dead load' depending on the layout.
Out of interest, the Brit Mil still do some EOLs on the Squirrel, they call them EOLs in that again the engine is back at idle but the throttle can be quickly opened to save embarrassment.
