I somewhat see your point (I think, but I'm an absolute noob at redstone, so I wouldn't know about things like that). But I acutally write datapacks mostly for myself and then post them online in case anyone else wants to use them, too.
So I'm honestly not too concerned about breaking some obscure redstone mechanic. I just want to make dead bushes renewable because they're currently not and they're good for decorating. If other people don't want to use the pack because of that, they don't have to. Also, like you already said, dead bushes aren't really all that useful in the first place (further supporting my point of not having to use the pack if you don't want to).
All of that being said, I'm still stuck on those files, though. I really would appreciate some help with that...