If half your set is made up of such cards, then you should have a much better chance of seeing any of them in a pack than the maybe one-in-five the last few years have seen
30% of Play Boosters contain an art card
Finally, colorless cards, such as some artifacts, do not have any colored mana requirements but still require a general amount of mana to be spent to play
I recently observed a French YouTuber opening the new Scarlet and Violet set (2 ETBs and 2 3 pack blisters) and saw a sequence of commons that were the same at least twice, so was wondering if it was a consistent and reproducible method which from your research seems to suggest so
Lands, Rocks, Ramp Since River costs three mana there is no rock, I can run to speed her up save Sol Ring so my rocks will look differently
Bonders Enclave ($1.50) Its in 151k decks online, theres no other special version and the chocobo art is not to be underestimated