I've read most of this thread (and all of your posts) op I sympathise. I have a very clever collie cross.
I have made my peace with the fact that I can control him but not the rest of the world.
The 'my dog is friendly' brigade - not cool. If my dog is on lead, he's calm and under control. If your dog then comes into his space and is winding him up then there's going to be a standoff. But you're not in the wrong. YOUR dog is Under control.
Sniffy walks, brain games, canicross secure fields are great. Don't beat yourself up the your dog needs to be off lead burning off energy. It's a bit of a myth.
We have yellow space vests/leads etc.
If other dog owners let theirs over to mine than that's their look out. I'm done worrying about the rest of the world.
My dog doesn't like lots of others dogs after being attacked. He doesn't need to meet them daily.
To me it's like me being made to go and meet people who look like the school bully. Why? I don't want to meet more people thank you. Just leave me alone!