So the best way to blast through is as follows:
Red tile wave 1 - mana charge Wilbur and then all heroes are charged again ready
Item through wave 2 - bombs and axes
Unleash specials and machine gun your Cillian/C.Colen using the mana boost from Lance to kill the boss wave
So there’s no scenario where the mana node makes a scrap of difference whereas a chance (however small) to double damage a tile is worth having