Ideally I would like a spigot plugin that makes the game pretend it’s “daytime” for the purpose of mob spawns, even at night. If this isn’t possible, I would also settle for a fabric mod that disables hostile spawns above sea level. Does this exist?
My use case is a “semi-peaceful” server; I want to make sure it’s always safe to explore the surface so that players don’t get ambushed by mobs when logging in at night, but I don’t want to completely remove hostile spawns because it would make some items and blocks unobtainable. I suppose a worst-case-scenario option would be to set the server to Peaceful mode and add crafting recipes for the missing mob drops?
What about allowing mobs to spawn in another dimension? Either the Nether and End or a second Overworld? It should be straightforward to get some code that lets you set difficulty per-dimension.