Just adding something: I hereby attest that R’ Shurkin, talmid of R’ Moshe, told me, personally, halacha l’maasa, that lift and cut is mutar lechatchila.
If I recall correctly, the lomdus was in relying on the rambam, and holding that electric shavers of which their blades are blunter than a razor’s and rely on speed to cut, are like mispirayim k’ein ta’ar which the rambam mater’s.
It takes a blade as sharp as a razor to be a ta’ar. One blade which cuts hair even when in slow motion. That is all I have to say about that.
