Quite right, rev, but para 2 discouraged except in those conditions specified since you can finish up with water (or melted ice) constantly refreezing over the upper surface and you can do nothing about it. You are right - I should not have said 'never'! (Repeat after me - never say never - never say never....)
I have always preferred (and been taught) to wait until I have an accumulation and then de-ice.