Here's my opinion...
a cyclic FLARE increases RRPM, regardless of speed. Concider this as a situation...
You are busy manually changing frequency and the engine dies (your hand not on the collective). Leading with a cyclic flare could (or will) assist in recovering RRPM until such time that you can lower the collective.
Therefore, during an engine failure after t/o, regardless of speed, FLARE. Just maintain SOME forward speed.
Again, my humble opinion.