If you combine the two ideas and you get the following:
Invasive acid and creates a Splotch, but nothing can stack.
In this form it might be OP, since your opponent is shut down with useless Splotches.
If you give Splotch the ability to produce random quanta, it'd screw monos, but not totally, giving them some chance with 1 random quanta / Splotch.
Just balancing I think. And to make this card useful in more scenarios and against more decks.
So this would help Invasive Acid to be useful against more decks. You could stop your opponent from further stacking pillars together and limit their Permanent spots. It would be OP against monos, since monos only need one type of quanta, they would be hurt even more heavily by this denial. You might not need the extra random quanta, it's just a suggestion for balancing it.
The point is: If you deny the opponent from stacking pillars and fill the permanent spots with Splotches it's much more successful than just filling the permanent spots and letting the opponent stack pillars.
As right now, Invasive Acid would only hurt decks relying on many permanents. If you don't allow the opponent to stack pillars, Invasive Acid will be effective against more decks.
I hope I managed to clear it up...