While it seems like you are trying to be considerate of others which is a good thing. I have to wonder if that local park does not require leashes at all times. I live a small state and all the local and state parks require leashes unless you are in the actual dog park areas.
So if your local park is similar, why wouldn't you just obey the law and use a leash the whole time you are in the park? If no leashes are required, but now you better control your dog when others are around, it sounds like you have really gotten a much better attitude towards other hikers and I congratulate you for that.