In terms of more improvements, the biggest inefficiency in the ending layers is the Serra's Sanctum / Animist's Awakening part, which gets us 2 layers for 4 cards. Of course, if we remove it we would need to find 3 other layers somehow to improve. We do have copying of triggered abilities and artifact activations, so that may open up new possibilities.
Well since my lore broker start didn't use panharmonicon its not strictly needed, so Arcane adaptation is an option.
Thrumming stone ends up being pretty slot efficient right? I don't quite remember how it works though.
Edit: I don't think thrumming stone works as it gives the ripple trigger to the spells, so it'd need to be a tribal spell to work with the Harmonic prodigy. And there aren't very many options for those.
Edit2:Harmonic prodigy even only works on permanents, so thrumming stone doesn't look like it works at all :/
Relevant comp rule: 109.2. If a spell or ability uses a description of an object that includes a card type or subtype, but doesn't include the word "card," "spell," "source," or "scheme," it means a permanent of that card type or subtype on the battlefield.
Oh, right I thought that was solved by Coat of arms based computation not really working if everything is the same creature type, but we can just point two kegs at a big keg as a whole computation, then dack the damaged keg once we have flash again.
Can we wrap drafna's restoration and uproot/plow under into the same card? Though a more general card like Noxious revival hitting creatures and enchantments is probably a problem... not to mention the use of using it on the oppon-
Oh, oof! Well, at the worst we can give up the land part of the layers, and drop to 9 layers I think. But, hopefully we can find a fix? I didn't see a card that could put a permanent into the library, but I might have missed something.
Of course Show and Tell can be replaced by Eureka, but that doesn't solve the problem. Another card we used before was Genesis Wave, but for that to work we needed Channel, which means we needed two additional green mana at the start. But, we need to keep green mana restricted if the goal is to try and keep that land part.
Hmm, we've realized that we don't need to update Busy Beaver, or update to Busy Beaver, all that frequently... we do need a hyperstage below it, but that can happen with any fixed number of layers, or even any fixed number of stages, above it. So I think so? We can afford to Retract between Busy Beavers, and we only need a fixed amount of mana for things like Urborg Syhpon-Mage and Soul Separator, so it should be okay.
The problem with sphinx is that its difficult to make more of them, as bouncing it is expensive. I guess we could kill it and make tokens via soul seperator, but then we need to get consecrated sphinx out of the yard too...
Hmm, yeah that is a problem. and plagues a lot of the ways we can cheat omniscience into play. Back to show and tell then?
Maybe there's an alternative to the plow under effect? Can't we just bounce the land and put it back on top with widespread panic?
But it'd need to be kind of expensive to work right, Crop sigil costs G which is a bit too expensive. Multani, yavimaya's avatar might work? It pays for itself through chrome mox, but needs both lands in play.
Edit: no just being a green creature makes too much green through bounce.
The thought was that multani going hand->imprint->grave->hand is neutral on green but requires an animist's awakening to get the second land back into play, so it doesn't go infinite with the worldfire transition.
But it can still be bounced for U/W mana and net green so it doesn't work.
Somehow there's nothing that bounces a nonbasic land.
Edit: the kamigawa moonfolk are kinda close too, though the two that return a pair of lands have bad effects Uyo, Silent prophet goes infinite copying animist's awakening Soratami seer is tricky but i think we can avoid decking ourselves with Wormfang behemoth Soratami mirror-mage looks like it works, but needs a third land.
Gah we can steal opponent's wastes so this does not work at all.
I guess we'll keep looking for how to get that 11th layer back; either find a replacement for Show and Tell, or find a way to get lots of land taps from a green mana that is compatible with Show and Tell.