Thank you for giving it another try! The rules for efficacy calculation are pretty much to use big particles (blue,pink,white), not repeat colour or letter ("zyz" bad, "boz" good), and have good synergy. The synergy value is determined by what particles are combined as it picks the value by sampling from a 3Dish noise texture using the particle makeup as coordinates for sampling (this one requires trial and error to figure out and even I don't know what particles combine to form the best synergy). 3.5k is a good score, especially considering how hard it is to grow particles up. I'll try and make a write-up to explain it a little better as someone suggested but I am happy you hear you had fun with it!