I think:

• Tag for all coralstone blocks (and items)
• Tag for all coralstone full blocks, stairs, slabs, chiseled, and walls respectively
• Tag for all coralstone blocks for each particular coral (and items)

I think neoforge is going pretty crazy with tags so this level of specificity might be permissible

:( https://github.com/thelegitdolt/dolt-modpack-how/blob/main/config/openloader/data/LootTable/data/dolt_modpack_how/loot_modifiers/drop_self/coralstone_drop_self.json

'Coralstone' isn't a standard across any mods and we don't have any use for the tag in the mod, so it is not needed within the mod. If a datapack needs those tags, they are able to define them themselves

it's something a lot of datapacks could conceivably need for recipes and standardizing saves time for everyone. It's not too different from having a tag for carpets and stained glass and cooked food and storage blocks for mulberries

Those are neoforge convention for both overlap and categorizing, like I said 'Coralstone' isn't an established standard and it's not something we would use in the mod, the only usecase I've ever seen for this is yours here, and you've already made the list

Alright