my 2 year old vizsla has a 95% recall in the yard, 60% on a long line at the park, and basically 0% off leash anywhere a squirrel exists and i am running out of ideas after 9 months

I need real help, not the "use higher value treats" advice, because i have done all of that. Hugo is a 2yo intact male vizsla, neutered six weeks ago (vet recommended waiting until 2 for growth plates, which is its own debate). We have been working on recall actively since he was 14 months when his teenage selective hearing kicked in. I have done online courses, two private trainer sessions, group classes, all of it.

Where we are. In our fenced back yard he is rock solid. I can call him off a squirrel on the fence line about 95% of the time. Slap a 30 foot long line on him at the local park and his recall drops to maybe 60%, mostly fine if there are no other dogs and no prey animals. Take that long line off in a place i thought was safe (a friends 5 acre property, fully fenced, no other dogs) and he turned into a different animal. Found a deer trail and was gone for 22 minutes. Came back on his own terms when he was good and ready. That was four months ago and i havent had him off leash since.

What ive tried. The "be the most exciting thing" approach (he is not interested in me when there is anything else worth chasing). High value treats (he will choose a deer over a tube of cheez whiz, asked and answered). E-collar with a balanced trainer (low stim, did get a more reliable recall on long line but i was uncomfortable with how he started checking back to me with that worried look, paused this approach to think). Whistle recall (works in yard, falls apart in field). Long line games (good for proofing but doesnt translate to off leash). Limiting access entirely (working but he is a vizsla and i feel guilty he hasnt done a real run in months).

What im asking. Has anyone actually moved a high prey drive dog from "great on a long line" to "trustworthy off leash in real environments." Did you keep going with the long line for years. Did you accept your dog is a long line dog forever. Did the e-collar work for you and how did you get past the worried check-in look that bothered me. Is there a training methodology i havent heard of. I love this dog and i want him to have a real life, but i also live near a road and i cannot trust this recall in its current state.