Not sure if this is intended behavior or not, but when I change a gamerule's default setting (in my case, natural regeneration), it works fine in-game. But the changes aren't apparent when creating a new world and going to the gamerules menu (i.e., natural regeneration is still set to true). The changes still apply when you load into the new world, but it's not reflected in that menu. Is it possible to change the values there?

I would like this as well. I'm adding this mod to my pack to force players to have natural regeneration turned off for more of a challenge in my peaceful modpack.

Ah so it is a cosmetic issue eh? I was wondering if the mod was just broke since it doesn't post to world rules on configuration page. Would it be better to make a globalgamerules-server.toml ? As in would that tell the main screen of the proposed updated rules or would it be better as a datapack?

Nah fam it isn't working at all. No matter what the config is set to, nothing in game is showing or using those changes. It is completely borked for 1.20.1, tested with forge 47.3.12 amd 47.3.0. and no other mods loaded.