While it would seem that the restrictions make Fires of Invention not particularly playable, it seems relatively easy to mitigate
While I wont be so bold to say that you should trade this in for something like Rampant Growth, I will say that more effects like this will be a welcomed inclusion in the format
2/2s every turn, lifelink on the larger body, and a similar saboteur ability to Gix, Yawgmoth Praetor all point towards this being a strong addition to grindy creature decks
If youre playing any kind of vehicles deck, youre going to A) be playing a lot of artifacts and B) playing more artifacts that arent vehicles, in order to maximize your artifact synergies
It also allows you to then cast a card from your hand with a mana value of X or less for free, which means you get even more value
Updates can lag behind the competition, and the deck builder isn't as polished as what you'd get from Moxfield or Archidekt