With 23H2, SYMPANpack moves to 1.20.1, adds new biomes and content mods like Better End, Better Nether, Another Furniture, Amethyst Imbuement and much much more.
Also, SYMPAN will open to the public (that means EVERYONE!) very soon! Stay tuned! ^^
How to Install:
Download the "Source Code" as a .zip and drop it into a MultiMC compatible launcher like ATlauncher or Prism Launcher (reccomended)