Like MO2 or Multi-MC you can create full seperate instances of mods for different playthroughs or modding experiences. Download the latest release and extract it into a folder Create two folders, one ...

1.12.2: Reads META-INF/fml_cache_annotation.json and get the annotation value, marks all client-only and acceptableRemoteVersions = "*" mods. 1.13+ Forge: Reads META-INF/mods.toml and filter mods with ...