As the number of players grows, the number of Reserved List cards remain static (at best), and prices increase
And though it isn't one of the specific examples listed by Magic judges, card size differences could be considered a form of marking
Try a Ruby Medallion to keep your red spells cheap, and use Koth, Fire of Resistance to dig up Mountains and keep the spells coming
Currently, Wizards of the Coast has only revealed two of the Scheme cards from Duskmourn: House of Horror
One pony had to be ranked last, but to be fair, Pinkie would probably be responsible for gathering every pony to play a game of Magic
However, for decks that dont revolve around the mechanic but still have a couple of Day and Night cards splashed in, it can provide an additional unneeded layer of complexity and mental load to the game