Corridors 

• Pots, vaults and doors to chambers line the walls
• Arrow and fire charge dispensers that can be shot at spawners
• Only part of the structure where the amount of spawners are random
• Dripstone can generate on the bottom to punish falling from the higher levels
• Spawners can have zombie variants, skeleton variants, spiders, slimes and pillagers

Ledge (originally called chamber 1)

• Similar ledge layout but platforms are lower
• Normal spawners: skeleton variants
• Tough spawner: jockeys

Chasm (originally called chamber 2)

• Original was just ledge but with powder snow, this is a new layout with a powder snow pit on the bottom
• Holes and trapdoors to drop down mobs
• NS: zombie variants, spiders, zoglins
• TS: big slimes

Cubic (originally called chamber 4)

• Basic layout like original but randomly generated
• NS: zombie variants, zoglins, slimes
• TS: wither skeletons

Crawl (originally called chamber 8)

• Mostly unchanged from original but added wind charge launchers to get to the next floor for fun
• NS: skeleton variants
• TS: ranged wither skeletons

Eruption

• Press every button on all 4 sides of the room to make lava pour from the center in a guided path
• NS: vindicators, slimes, pillagers
• TS: breezes

Pedestal

• Try to cross the gap to the spawners with trapdoors and unique extending platforms
• NS: slimes, pillagers, phantoms
• TS: witches (remember: honey bottles cure poison)

Assembly

• Fight a breeze on the bottom, climb up the parkour section at the back, then fight ranged mobs on the hanging platforms at the top
• Bottom section has traps for breezes to trigger such as potion dispensers, trapdoor pits, and deadly rocket dispensers
• Throw wind charge on the hanging platforms to expand their size
• NS: zombie variants (bottom), skeleton variants, pillagers (top)
• TS: breezes

Slanted

• Chamber is split into mini chambers in each corner designed for fighting a specific mob type
• More of a maze-like layout between enemy rooms
• NS: skeleton variants, spiders, phantoms, vindicators, drowned, creepers
• TS: vexes

Ladder (new!)

• Climb up the ladder of platforms, each with a spawner, along with blazes shooting at you from the top
• Create staircases with the chiseled copper mechanic
• Knock mobs down the middle to land on dripstone
• NS: spiders, zoglins, pillagers, slimes
• TS: blazes

Channel (new!)

• Water themed chamber
• Soul sand shoots mobs above water incase you try to escape
• NS: drowned, trident drowned
• TS: guardians

Crash (new!)

• Explosive themed chamber about destroying the terrain you fight on
• Chamber is trapped to punish reckless explosions
• Ghasts shoot you while kept in place
• NS: creepers, zombies
• TS: ghasts

Cargo (new!)

• Mobs and the player can ride along constantly shifting rails
• Activate the secret to ride to the top rails and fight the tough spawner
• NS: skeleton variants, pillagers, spiders, phantoms
• TS: rocket pillagers

Streak (new!) (1.21.4+)

• Use speed potions and soul speed to avoid fast melee skeletons
• Avoid tripwires that open the tough spawner's cage
• NS: melee skeletons, husks
• TS: creakings

 All mobs are split into the "normal" and "tough" category. Each chamber has 3 normal mob spawners and 1 tough mob spawner. A good amount of the mobs have been altered for balance and convenience.
("O." is short for "ominous")

Normal category

Zombies
  O. adds rebalanced armor and ench. bows

Husks
  ^

Drowned
  ^

Skeletons
  O. adds rebalanced armor and ench. bows

Strays
  ^

Bogged
  ^

Spiders
  O. changes some spiders to cave spiders

Slimes
  O. changes to magma cubes

Pillagers
  O. crossbows gain multishot and quick charge

Vindicators
  Base attacks with hands
  O. gains wooden sword

Zoglins
  O. increases damage and knockback

Creepers
  O. changes to (nerfed) charged creepers

Phantoms

Trident Drowned

Melee Skeletons

  O. gains soul speed boots

(baby zombies and silverfish are completely removed)

Tough category

Base vaults are split into three: armor, valuables, and weapons. This will let you (partially) customize your loot and opt out of stuff you don't want. All 3 vault types will always be found grouped together. The structure will generate plenty of these incase a player wants to use all of their keys on only one category. Luck adds a 33% chance to dispense double the loot. Aesthetic based loot (sherds, banner patterns, trims) are moved to hidden chests in intersections so that they don't get in the way of the more useful vault loot.

Armor table

Valuables table

Weapons table

Ominous vaults are still a single category. You will get both types of keys from ominous spawners so the ominous vaults will act as an enhancement to the loot the other vaults give you. 

Ominous table

Pots can hold wind charges or less valuable ores, such as lapis, copper and redstone. You'd likely find this structure while mining, so this is meant to synergize with that. 

Tridents and heavy cores are reserved for bosses. Once defeated, the main boss spawner will dispense a trident on normal difficulty or a heavy core on ominous. This gives you a 100% chance of getting these items per trial chamber (unlike the very low chances per vault from vanilla) in exchange of the added difficulty from the bosses.

Food will be dropped by tough mobs instead of them filling up vault loot tables. 

This is something I particularly want to balance well, so feedback would be appreciated!

Trial chambers contain 4 exclusive enchantments to act as another incentive for grinding vaults. All are single level, situationally powerful, and changes the behavior of the weapon sort of in the same vein as channeling or silk touch. Ominous vaults have a 25% chance of ejecting a book containing one of these but only if the player has the luck effect.

Daredevil: Creates an explosion on the opponent if hit with a mace's smash attack and deals massive damage, but also damages you depending on how close you are.

Storm Front: Causes a wind charge explosion wherever a trident is thrown. Acts as a renewable wind charge. Incompatible with riptide.

Equity: Axes mimic Flame II and Knockback II (along with a small damage increase) when attacking an entity holding a sword.

Razor Tip (1.21.11+): Spears deal 2x damage if a hit is landed right at the tip of your attack range. The bonus damage range increases if the player's attack reach also increases (including creative mode). 

There are 5 different boss chambers at the end of every trial chambers, each with unique mechanics and difficult mobs. I want most of these to stay a surprise so there won't be much detail here. Defeating a boss on normal difficulty will reward each player a trident. Ominous difficulty will reward a heavy core instead. While you always can run straight to the boss to get a trident/heavy core if you really wanted to, you'll be missing out on all the other loot the structure has.