any kind of subjective experience a plant has would be on a very long timescale

Why would that be an issue? Are sloths less capable of pain because they are slower?

And you’d have the weird situation where it’s mind “grows” as it’s thinking

Why would be an issue with that? Kids brain grows and you have no issue with acknowledging their mind? It is not too hard to imagine?

For sure, people treat a dog as if it has pain, and lettuce as if it doesn’t, and I’d be surprised if you wanted to change that.

What a strange assumption on my intentions…