Looking at the data gathered by the community so far, this does ring true
The Spike Considering how little attention Green Goblin garnered in Commander leading up to Marvel Super Heroes, it used to be quite cheap
This means that, after initially being cast, Kroxa's controller will never be required to pay Commander Tax, as Kroxa can merely be cast from the graveyard.
The other way Dual-Ink cards will help is by improving lower-tier decks and strategies
If you're playing a dedicated artifact deck, being able to make extra bodies is great, and if you're playing a dedicated Dinosaur deck, you can get a ton of Treasure tokens to ramp into your high-mana Dinosaurs
Waterbending allows you to reduce the cost by by tapping a creature or artifact you control, and you can do this as many times while paying the cost