I do believe ForgeLab's pack has a variety of issues that needed to be worked on, so I did just that, list of what I generally did to "fix" it (subjective)

• Balancing Issues := Usage of Reskillable mod to have a rough control of progression, tweaked recipes, and a variety of gameplay-focused changes to improve playability
• Performance := Added Radk6's performance mod list, support for Cleanroom launcher, and GREATLY improved world generation by the usage of Recurrent Complex to replace the mod gen of almost all of the included mods, expect far far better performance.
• Outdated Mods := Updated a variety of mods and fixed compatibility issues down the road.
• Lack of an Issue Tracker := Uses GitHub for issue tracking.
• Lack of QoL := Added a variety of custom recipes, zenscripts, and mods (along with some own-made mods) to improve playability.
• Old Look := While not an issue I have recommended below (refer to the 'Requirements' section) the best options for a more modern look if you are into that.

Starting in May 2023, this was a project I had in mind after I saw ForgeLab's "100 Days in a Parasite Outbreak" video, and yes, this pack has a complete quest system in mind.

Cleanroom is, in simple words, a new Forge fork that makes 1.12.2 work with Java 21 (ooo shiny new) instead of Java 8 (boo old java!) which in general is a big improvement in performance, security, and a lot more (AFAIK)

I recommend using Cleanroom with GraalVM Java 21 as its the best in raw performance and has the shortest load times.

System Type x64-based PC

Processor AMD Ryzen 5 3600 6-Core Processor, 3600 Mhz, 6 Core(s), 12 Logical Processor(s)

Installed Physical Memory (RAM) 16.0 GB

Total Physical Memory 15.9 GB

GPU Nvidia GeForce GTX 1650

RAM allocated in Minecraft is 4GB.

Fogger does not render properly in survival mode effectively making the mod useless, instead I opted for Fog Tweaker.

Spider 2.0 causes AI-less skeletons to appear randomly in the world, thanks for u/PhantomishHawk for pointing this out on this reddit post.

SHADERS DO NOT WORK; this is a known issue of Optifine with this modpack, no current or future fix planned. ALTERNATIVES: Resource packs.

OPTIFINE'S Fast Render AND Fast Math BREAK THE GAME, IF YOU ENABLED THEM YOU WILL HAVE TO EDIT THE CONFIGURATION BY HAND.

• antiqueatlas-1.12.2-4.6.3.jar := Granted (GNU GENERAL PUBLIC LICENSE)
• AtlasExtras-1.12.2-1.8.jar := Granted (CC BY-NC-SA 4.0)
• AutoJumpAutoOff-1.0.2.jar := Granted (ARR but told modpack usage is OK)
• BetterPlacement-MC1.7.10-1.0.0-1.jar := Granted (Mozilla Public License Version 2.0)
• BlockOverlayFix-1.12.2-1.0.0.jar := Granted (MIT)
• ChunkAnimator-1.12.2-1.2.1.jar := Granted (MIT)
• CraftStudioAPI-universal-1.0.1.95-mc1.12-alpha.jar := Granted (Apache License Version 2.0)
• CreativeCore_v1.10.71_mc1.12.2.jar := Granted (GNU Lesser General Public License)
• DefaultOptions_1.12.2-9.2.8.jar := Granted (ARR but told modpack usage is OK)
• Forgelin-1.8.4.jar := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• FriendlyEndermite_v1.0.1_mc1.12.2.jar := Granted (GNU Lesser General Public License)
• IvToolkit-1.3.3-1.12 (1).jar := Granted (Apache License Version 2.0)
• PlayerRevive_v1.2.40_mc1.12.2 (1).jar := Granted (GNU Lesser General Public License)
• PocketNetherLink-1.12.1-2.6.jar := Granted (ARR but told modpack usage is OK)
• ReachFix-1.12.2-1.0.9.jar := Granted (MIT)
• RecurrentComplex-1.4.8.5.jar := Granted (MIT)
• SmoothWater-0.1.4.jar := Granted (GNU Lesser General Public License)
• SoundFilters-0.12.1_for_1.12.jar := Granted (ARR but told modpack usage is OK)
• VariedCommodities_1.12.2-(31Mar23).jar := Granted (Creative Commons Attribution-NonCommercial 3.0 Unported)
• WTS-1.1.0.jar := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• [1.12]MoVillages-1.5.4.jar := Granted (Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Public License)
• animania-1.12.2-base-2.0.3.28.jar := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• betterhud-1.12.2-1.4.4.jar := Granted (MIT)
• jeivillagers-1.12-1.0.2.jar := Granted (MIT)
• overloadedarmorbar-1.0.4g.jar := Granted (MIT)
• roughTweaks0.2.4-1.12.2.jar := Granted (ARR but told modpack usage is OK)
• unloader-1.2.0.jar := Granted (MIT)
• SpiceOfLife-mc1.12-1.3.12 (1).jar := Granted (Public Domain)
• AnimEmis_srparasites := Granted (MIT)
• Emis_Rlcraft := Granted (MIT)
• alcatrazcore-1.0.4.jar := Granted (GNU GENERAL PUBLIC LICENSE)
• anvilpatch-1.1.0.jar := Granted (MIT)
• AppleCore-mc1.12.2-3.4.0 (1).jar := Granted (Public Domain)
• AquaAcrobatics-1.15.4.jar := Granted (Public Domain)
• BetterFps-1.4.8 (1).jar := Granted (GNU Lesser General Public License)
• BetterSigns-1.0_v1.12.2.jar := Granted (GNU GENERAL PUBLIC LICENSE)
• cleardespawn-1.12.2-1.0.jar := Granted (MIT)
• CompatSkills-1.12.2-1.17.0.jar := Granted (MIT)
• DarknessLib-1.12.2-1.1.2.jar := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• DeathCounter-1.12.2-1.1.0.jar := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• DynamicTrees-1.12.2-0.9.29.jar := Granted (MIT)
• EnhancedVisuals_v1.4.4_mc1.12.2.jar := Granted (GNU Lesser General Public License)
• EntityDesyncFix-1.12.2-1.0.2.jar := Granted (MIT)
• EyesInTheDarkness-0.1.0.jar := Granted (BSD License)
• Grue-1.12.2-1.8.1.jar := Granted, credits to Shinoow for the cool mod <3 (ARR but should credit OG page and credit author)
• InventoryTweaks-1.63.jar := Granted (MIT)
• itemzoom_1.12.2-1.11.jar := Granted (MIT)
• Jade-0.1.0.jar := Granted (current version is 1.15- so license is MIT)
• JustEnoughResources-1.12.2-0.9.3.203.jar := Granted (custom license but told modpack usage is OK)
• Locks-1.12.2-3.0.0.jar := Granted (Creative Commons Attribution-NonCommercial 3.0 Unported)
• mekatweaker-1.12-1.2.0 (1).jar := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• MoBends_1.12.2-1.2.1-19.12.21.jar := Granted (MIT)
• MouseTweaks-2.10.1-mc1.12.2.jar := Granted (BSD License)
• mysticallib-1.12.2-1.13.0.jar := Granted (MIT)
• mysticalworld-1.12.2-1.11.0.jar := Granted (MIT)
• NoCubes_SRP_Combat_Addon_3.0.0 (1).jar := Granted (ARR but told crediting is necessary)
• NoCubes_SRP_Survival_Addon_3.0.0.jar := Granted (ARR but told crediting is necessary)
• nonetherportals-1.1.0.jar := Granted (GNU GENERAL PUBLIC LICENSE)
• notreepunching-2.0.21 (1).jar := Granted (MIT)
• RawOre (1).jar := Granted (Academic Free License ("AFL") v. 3.0)
• Reskillable-1.12.2-1.13.0 (1).jar := Granted (Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License)
• RLCombat-1.12.2-2.1.0.jar := Granted (MIT)
• RLMixins-1.3.4.jar := Granted (MIT)
• SereneTweaks-1.0.jar := Granted (Creative Commons Attribution-NonCommercial 3.0 Unported)
• SimpleDifficulty-1.12.2-0.4.0.jar := Granted, NOTE: Own fork (MIT)
• SmoothFont-mc1.12.2-2.1.4.jar := Granted (ARR but told modpack usage is OK)
• smooth-scrolling-everywhere-1.1.jar := Granted (Apache License Version 2.0)
• SnowRealMagic-1.12.2-0.7.1.jar := Granted (MIT)
• SpartanWeaponry-1.12.2-1.5.3.jar := Granted (Apache License Version 2.0)
• ToroQuest-Revamped-3-25-2022-fix (1).jar := Granted (GNU GENERAL PUBLIC LICENSE)
• waterproof2-1.0.0.jar := Granted (CC BY-NC-SA 3.0)
• swparasites-v1.1 := Granted (GNU GENERAL PUBLIC LICENSE)
• BetterQuesting-3.5.329.jar := Granted (ARR but told modpack usage is OK)
• StandardExpansion-3.0.181.jar := Granted (ARR but told modpack usage is OK)
• nocubesrptweaks-V4.1hf4.jar := Granted (ARR but told crediting and no monetary features)
• VeinMiner-1.12-0.38.2.647+b31535a := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• GlobalGameRules-1.12.2-2.2.7 := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• Waystones_1.12.2-4.1.0 := Granted (ARR but told modpack is OK)
• Alfheim-1.4 := Granted (MIT)
• censoredasm5.20 := Granted (GNU LESSER GENERAL PUBLIC LICENSE)
• StellarCore-1.1.11 := Granted (GNU lesser general public)
• UniversalTweaks-1.12.2-1.12.0 := Granted (GNU lesser general public)
• vintagefix-0.5.1 := Granted (GNU lesser general public)