If you are looking to downgrade or manage game versions, here are the common community-driven methods: Community Downgrade Methods
: You can manually swap version files by navigating to the game folder and renaming the .SkuDef files. For example, renaming CNC3_english_1.9.SkuDef to an older version's name can sometimes trick the launcher into using those settings. Command And Conquer 3 Tiberium Wars PC Game Dow...
If you meant "download features" or general game capabilities: If you are looking to downgrade or manage