Allocating 7+ GB is recommended, less in multiplayer.
My second modpack is much less demanding for the player's hardware and is what I still use for my main multiplayer world.
I'm currently preparing this pack for our own use.
____________________
Xp is disabled.
The Silk Touch enchantment is craftable for diamond tools with a slimeball. The Prehistoric Nature time reversal enchantment for the bone wand is crafted with an ender pearl. The Prehistoric Nature archeologist and paleontologist enchantments are craftable with paper. The Fossils and Archeology discerning collector enchantment is crafted with paper.
The most useful items being Davinci's boats, realmite pickaxes, rupee shickaxes, aether 2 holystone shields, electric furnaces, muskets/blunderbusses, aether 1 orange moas and Bibliocraft atlases.
I've excluded mods that bring forms of automatic mining or drills.
Into the Maelstrom griefs the world too much, the skill system in Advent of Ascension is too intrusive, Yung's dimension and dungeon mods were still in a clear beta state in 1.12.2. The structures in Roguelike Dungeons are cool but have no bosses, Chocolate Quest and Unseen's Dungeon Additions already fill the world with dungeons. Advanced Rocketry has a better system for travel but this modpack is dungeon based and Galacticraft offers the same planets.
I haven't found a scuba diving mod that doesn't make swimming overpowered or unnecessarily changes skin diving mechanics.
Some compatibility issue is preventing me from adding LittleTiles.
____________________
Dimensions:
1. Abyssalcraft (4)
2. Atum 2: Return to the Sands
3. DivineRPG (8)
4. Fossils and Archeology: Revival (2)
5. Galacticraft Legacy (4)
6. Galaxy Space addon (23+)
7. More Planets addon (12+)
8. Zollern Galaxy addon (12+)
9. Prehistoric Nature (9)
10. The Aether (+ Continuation and Lost Content)
11. The Aether II: Phosphor Not Included
12. The Aurorian
13. The Betweenlands (+ Betweenlands Redstone)
14. The Erebus
15. The Midnight (+ Midnight Rifting Machine)
16. The Twilight Forest - Deforestation Edition
17. Tropicraft Legacy
18. Wyvern Lair (Mo' Creatures)
Dungeons and Bosses:
1. Chocolate Quest Repoured
2. Unseen's Dungeon Additions
Misc:
1. ArchitectureCraft - TridentMC Version
2. Balkon's WeaponMod: Legacy (+ Balkon's Expansion)
3. Better Gold Stuff
4. BetterNether
5. BiblioCraft
6. Biometweaker (no scripts)
7. Camera Mod
8. Chisel
9. Chisels & Bits
10. Clay Soldiers Mod
11. CraftTweaker
12. Davincis Vessels (airships are disabled by default)
13. DupeFix Project
14. Glass Shards
15. GraveStone Mod
16. Ice Shards
17. Immersive Railroading
18. Inventory Tweaks
19. Iron Chests
20. Just Enough Items
21. LemonSkin (AppleSkin Fork)
22. Mineshot: Screenshot Utility
23. Mo' Creatures Extended
24. NetherEx
25. No Default Auto-Jump
26. OpenComputers
27. OreCrafting
28. Patchouli
29. Replay Mod
30. Stygian End Re-Continuation
31. Unexperienced
32. YUNG's Better Mineshafts
Optimization mods:
1. Alfheim
2. BetterFps
3. Entity Culling
4. Particle Culling
5. TexFix
6. VintageFix
Dependencies:
1. AsmodeusCore
2. ConnectedTexturesMod (for custom resource packs)
3. GeckoLib
4. LibraryEx
5. LLibrary
6. Mixinbooter
7. MixinBootstrap
8. MovingWorld
9. Nether API
10. Reach Fix
11. Red Core
12. RenderLib
13. Roughly Enough IDs
14. SanLib
15. SteveKunG's Lib
16. Track API
17. Universal Mod Core
Resource Packs:
1. Connected Textures for Davinci's Vessels
2. Connected Textures for Galacticraft
3. The Official Connected Textures Pack