Abyssal Depths+

Very important: Remember to push the SWL data pack to the top before creating your world; otherwise, the game for some reason doesn't generate past vanilla.

Description before mod list:

Abyssal Depths+ is a hardcore survival-focused modpack that expands Minecraft's vertical world build limit to roughly 1024 blocks above sea level and 512 blocks below bedrock. The pack enhances exploration, resource gathering, and long-term survival while remaining relatively close to vanilla gameplay. Players can expect a larger world to explore, increased progression depth, and a more challenging survival experience. 

List of mods:
AI-Improvements (Makes the monsters less stupid)
BetterDays (Makes the days and nights longer)
BetterF3 (Makes F3 not so messy, but has some downsides)
BiomesOPlenty (Adds more biomes)
BrandonsCore
Buildcraft (Mid-game items, can be used for auto-mining)
BuildcraftRF (Not working)
Caves+ (Improves caves)
Cloth-Config
Clumps-Forge
CodeChickenLIB
ColorfulHearts (Makes hearts less annoying if you have a lot of them)
Corgilib
CrashAssistant
Curios
CyclopsCore
Data_Anchor 
deeperdarker (Makes ancient villages more interesting as well as gives the warden a use besides being a boss)
deeper-oceans (Self-explanatory)
Draconic-Evolution (Late-game items, adds well, a lot of OP stuff)
Draconic-Additions (Adds chaos items, very late-stage items; I normally wouldn't go for these items until endgame, though )
DynamicLights (Makes it so lights act the same as in real life; hold a torch, and and it makes your surroundings glow)
DynamicTrees (Makes trees well; honestly, I think they give more items than regular trees, but that could just be me; it also makes them look better.)
DynamictreesBOP (Dynamic tree but for biomes o plenty)
ElementaryOres (More ores)
Embeddium (Needed for shaders, Oculus)
EnderStorage (Mid-Late game storage; if rushed, you can obtain it early game.)
Enhanced-Celestials-2 (Different moons, examples being a blood moon)
EpicTerrain
EverLastingAbilities (Gives you permanent potion effects in exchange for levels)
Flib
Geckolib
Glitchcore
HigherHeightsUltimate (this is an extension to SWL, separate mod but does the same thing except only for height)
ICeberg
Ironchests (Early game storage)
Ironfurnaces (Early game to late game furnaces)
Jade
JEI (Makes getting item recipes or looking for a specific item easier.)
JSG (Stargate mod)
LegendaryToolTips
Lithostitched
Mekanism (Needed for MGenerators)
MekanismGenerators (Good for stargates and other tech mods)
Modular Forcefields (This is... like Draconic Evolution a bit on the tech side, good for late-endgame stage)
MoreAndMoreArmor (It adds more armor as the mod name says)
MouseTweaks
Oculus (For shaders)
Prism
RefinedStorage (Better method for storage; it's mid-late game)
SereneSeasons (Pairs well with Tough as Nails, as its mod name describes it; literally adds seasons)
StreamsReFlowing (Disabled)
SWL (Shattered World Limits): Increases height and depth limits; this is where you get your increased depth and height.
TerraBlender
Tough As Nails (Self-explanatory; it makes the game harder by adding temperature and a thirst bar.)
Vein Miner (Not sure if it works; so far I haven't had any luck, but it should help you mine all ores by breaking 1 ore block)
Volcanic Caverns (Makes caves better and... More dangerous for those who mine straight down)
WorldEdit
Xaero Minimap
Xaero WorldMap
YungsAPI
YungsBetterNetherfortresses

Also, please take note that it's recommended to have at least 12 GB of RAM. I loaded into a world, and it was consuming 6.2 GB by default when I first spawned in.