https://www.reddit.com/r/mtgcube/comments/4r8ota/modified_the_cmc_of_some_cards_for_my_legacycube/
Yeah, Connoisseur is a great 3 drop.
Oh my god I'm so going to play at least one cmc-modded card. That's brilliant! For people who haven't clicked the link, basically you just cut out a generic mana symbol from some limited fodder, scrape it down to a really really thin peace and glue it on top of the generic mana of your card you would want to cube if it would be a little cheaper costed.