Similar to the way that tile entities can store inventories it would be cool if we could add fluid storage I don't know how it works but I know it comes with forge for an example look at the mod ceramics or literally any popular tech mod or tinkers construct you get the idea
Issue comments
The FE system uses the IEnergyStorage, and there's also fluid storage using IFluidHandler.
https://mcforge.readthedocs.io/en/latest/datastorage/capabilities/
yes, Forge does have a fluid api:
https://ftbwiki.org/Liquid_Registry
Check out ceramics for an example:
https://www.curseforge.com/minecraft/mc-mods/ceramics
Merged with: https://mcreator.net/tracker/issue/42538
Fluid storage can be implemented already by checking blocks (for fluid) and NBT tags of blocks to store fluid levels in the blocks.