Hey Hivemind, haven't been real interested in Turbo Depths lately, but Scheming Symmetry piqued my interest again -> checking to see if anyone been experimenting with it.
https://scryfall.com/card/m20/113/scheming-symmetry
Seems to me this card would be pretty sharp as a one mana tutor finding combo piece, pithing needle, or thoughtseize.
If you turn one scheming symmetry, I dunno if opponent would force of will it straightaway, but then they are either looking for wasteland or swords to plowshares. If they grab wasteland they may have had one in hand or were gonna draw it anyway and now have to play it to prevent you from going off the next turn and you can just needle it. If they grab plowshare, you can just thoughtseize, safekeeper, or therapy it/them away.
Later in the game, you would probably be scheming for card like needle, cabal therapy, life from the loam, decay, trophy, or maybe a good sideboard card.
Below is my old list. I am currently testing replacing 3 assassin trophy with 3 scheming symmetry and replacing thoughtseize with cabal therapy. I just noticed that trophy actually nullifies the top deck on their end, dunno if any other cards can do similar. On my end ancient stirrings can immediately get the tutor to hand.
4x Ancient Stirrings
4x Bayou
1x Bojuka Bog
4x Crop Rotation
4x Dark Depths
4x Expedition Map
1x Forest
4x Lotus Petal
4x Pithing Needle
4x assassin's trophy
1x Sejiri Steppe
1x Swamp
4x Sylvan Scrying
4x Thespian's Stage
4x Thoughtseize
4x Urborg, Tomb of Yawgmoth
4x Vampire Hexmage
4x Verdant Catacombs
Kinda an edge case also, but one of the things that disappointed me in the deck was lack of cantrip suite and sometimes getting dorked on green mana - symmetry could also be used to grab green land in a bind.