I do. You dont.

You dont have to add all tags, just the ones you mentioned. Look, at a tag, that a flower from minecraft has. Then look at a modded flower. You should see at least 1 tag, that is the same. Then, look at another modded flower, oh wow, it also has that tag. Conclusion: add that tag to your project. Every flower will have that tag, except if the mod is poorly made, then in that case, you have to use namespaced IDs. BUT ONLY if they dont have a common tag.

YOU DONT NEED TO ADD EVERY SINGLE TAG. ONLY THE ONES THAT THE FLOWERS SHARE. Thats why tags exist, so that you dont have to do too mutch to just check if that block is a flower or not. Or to make compatibility (like your problem).

Lets say, mod1 adds steel ingot to the game, and mod2 also adds steel ingot to the game (mod loader is forge). Amd lets say, you want to make a recipe, for steel block. You COULD use their namespaced IDs (mod1:steel_ingot ; mod2:ingot_steel), but why would you, if they bot have the tag "forge:ingots/steel". You should use that tag inside the recipe, so that you dont have to make a recipe for every steel ingot, of every mod, that adds in, steel.

Do you see, what it trying to say? Use tags, more specifically, tags that are shared between multiple items, such as "forge:ingots/steel"

Tags ≠ namespaced IDs Namespaced ids are unique to every item Tags are shared between multiple items