Teleport Mana Refund - Refunds 0 Mana Spells

I would really like it if the mana refund node for teleport only affected spells with a mana cost. It is pretty hard to make it work in builds that are trying to reduce mana in general because if you have any spells you are using that costs 0 to keep overall costs low so your main skill is the only mana hungry thing, the 0 mana spells constantly eat the refund if you use teleport to move around. I don’t see why it should attempt to refund things that cost no mana anyway.