I just finished watching. I think that the zombo blocks are spawnable, (iron golem can spawn above zombo room)

Hi Cub,
Regarding Minecraft: The List, (replied to ep.3 post)

-other idea: Multi-effect potion.
similar to book enchantment, to combine potion effect in one potion. this addition to potion recipes, and other changes you mentioned.

Forgot to mention that Dripstone already have water drips.

This also can be added as a feature for the End update.
Block tied to dimension (Mogswamp); Bed = overworld, Respawn Anchor = Nether, Ender Depot = End. (Cubfan)
Ender Depot could also consume player head to link inventory. it will self load similar to Ender Pearl but without loading chunks.

-Inventory;
Ender Depot: Add player head to Ender Depot Recipe. (Minecraft: The List- Episode 11)
Introduce a way to obtain player head. player head will link Ender Depot to one player by the tag.
Ender Depot maybe work in the end dimension only;
Nether can warp space (8 block)
End warp Inventory?

This allows player to obtain Heavy Core without needing to explore so many Trial Chambers regardless of the RNG.

-Resetting Vaults: need time & cost to reset vaults, the cost could be Netherite Ingot because of the high rewards from vaults, and multiple people can use it after one reset. but not too high of cost to balance single player cost.

-Trading: you mentioned some solutions, here are more.
Enchanted Book are tied to villager biome type. same to frogs and frog light types are tied to biome.
-Mending trading: tied to the igloo villager when cured. (adding to Episode 10 of the list)

-Sand & Red Sand: renewable,
Dye sand to obtain other types.
-Renewable; Use wind charges to convert Stone to Gravel to Sand to Clay? it could be a chance based thing (Wind Erosion)
-Soul sand to be converted to sand if mobs breeding was on top of the Soul sand. (use of Bartering)

-Nether Bricks & Red Nether Bricks variants: using stonecutter to create more variants similar to stone.
You mentioned Granite, Diorite, & Andesite on the list before.

-Concrete used in stonecutter: for slaps, walls, & stairs.

-Crimson Nylium & Warped Nylium: similarly, crafting both of these using their Fungus type.

-Podzol & Mycelium crafting: (By you)
you mentioned the crafting of Podzol using leaf litters,
you could also use mushroom to craft Mycelium, sometimes its hard to find Mycelium.

Spore Blossom, Firefly Bush, Creaking Heart, Leafs. all emmets particles.
This change could introduce more Atmosphere into buildings and games.

-Copper crate: To create atmosphere.
waterlogged crate can create rain Atmos/Particles.
waterlogged crate on campfire will create fog cloud on top (like Firefly Bush.)
powdered snow on top of Copper crate can create snow Particles.
All these are similar to things already in game;

In addition, Fully Rusted iron/weathered copper Minecart can stop mobs AI, which will prevent some lag and can be used as a block that holds no AI mobs. Note that you can only craft iron or copper Minecart and let it set to change state with the mob. you cannot pick mobs after fully rusted.

-Minecart speed control: speed controled by redstone signal.
Copper Minecart would be more conductive and have more speed.
Rusted iron Minecart could be slow.
Minecart can change rust or weathered state only if not in rails, which will prevent breaking older farms and michanics. (by you and others)

-Happy Ghast can have speed potion effect. (by you)
-You can place block on Happy Ghast on air. its made for building, but you have to scaffold up to build? (by Mumbo)
-Map utility; you can combine maps into one item to use when explore, like mini map mods, but more minecrafty. (by Xisuma)

Hello Cub,
If you ever go back to Minecraft: The List.
there are some suggestions that could be added. I didnt know how to send it to you but I can type some here.
(most suggestions made by hermit or others)