Extreme Optimization!

Some third-party launchers are unable to install older versions of Forge, you can use 1.12.2 Forge Vanilla Launcher.

Highly recommend these mods, not added to the modpack, because they do not correspond to the concept of extreme optimization and "Base", but may be more useful than others QoL mods:

AntiGhost - Get rid of ghost blocks by requesting resends from the server.

JEI - Item and recipe viewing mod for Minecraft, built from the ground up for stability and performance.

REI - JEI alternative.

* "Dependencies" shows only 90% of the mods in the modpack.