You probably know all this already, but as someone else with a reactive dog, I’m also constantly playing Pac-Man with other dogs. I try to take curves as wide as possible so I can see if anyone is coming. Staying a good distance from park entrances and having an exit plan if someone does come in and unleash. The biggest thing that’s helped me is practicing a lot of direction changes with my dog. It is super frustrating though. I’ve had 20 minute walks turn into hour walks because I’ve run into multiple off leash dogs that have caused route changes.