Increased Mana Cost on Tree

Can we please get more/better options for increasing mana cost on the tree? We can get a maximum of 15%, from two nodes, all thanks to old Archmage. Now that it functions differently, surely these nodes can be buffed or an increased/more mana cost mastery can be added to the tree. Or maybe more flat increased mana cost modifiers can be added back to the game (RIP old Doedre's Malevolence).

It's made Stormbind difficult to scale early game (prior to Indigon). Octavian has already stated that he finds it the most interesting skill that doesn't fit PoE 1, I feel like this would help that.

It would also help diversify Manaforged Arrows builds, they might be at least a little bit functional without Indigon.