Some modules can be easily merged to core - Hydro, Vokayra, Platyping, StrategyOnly and some others. Moon Colony can be merged to Pepper's module. All art and schema was moved from modules to core, and soon building/unit classinfo files will be gone (merged into unit/building infos). I think only alt timelines, some DH modules, Pepper's module (merging Earth content to core would be preferable) and few others can stay here - traits and deactivated ones, maybe animal placing too. Existence of modules complicates stuff, since they have default tags, that cloud searching stuff in Notepad++. Also they may be overwriting stuff in core.