Yes...good point about the harness. They do have some...but they are too small even at the smallest size. Even the cat ones didn't fit nicely. However, we have not been walking or anything. They just got their last set of shots last week so we could, but the weather is turning cold. I think it will fit better in another pound.
We use the leash when I let her out to do her business, but I make sure to be gentle. She doesn't pull on it. She has an expandable leash so she just does her stuff and comes inside again.

I can't let her run free. I have no fence in my yard.