There's always a valid reason to downrank Life Tap. It's commonly downranked one or two ranks to consume less health and/or avoid overflowing on mana. Currently, only rank 1 is ignored. This is a common rank to use since it's able to proc certain spell effects, but other ranks are needed when the goal is to restore mana without wasting health. I think the best solution is to ignore all ranks of Life Tap.
There's always a valid reason to downrank Life Tap. It's commonly downranked one or two ranks to consume less health and/or avoid overflowing on mana. Currently, only rank 1 is ignored. This is a common rank to use since it's able to proc certain spell effects, but other ranks are needed when the goal is to restore mana without wasting health. I think the best solution is to ignore all ranks of Life Tap.