I think it's his german shephered half that's come to the fore as he matures that earns the trust ...
There's a few huskies and malamutes in the area, very few are allowed off lead unless they're in an enclosed area. There's a big parkland/woodland area 5 minutes walk away where mine gets to walk/run, and he'll have a runaround with any other dog that's up for it. That includes a brother/sister pair that we've been meeting since they were 14 week pups and are now allowed off lead in certain spots. Were never sled dogs so their instinct is probably lessened.
I also have 36 golf holes about 400 yards from my door where he'll chase a ball all day long, either when the course is weather closed, or on a quiet loop (holes 2-7 on one of the courses - 2 is downhill, 3-6 a loop, 7 is back up the "heart attack" hill) where golfers won't go after a certain time of day. Been a member there since 1998 so I know the times of day/year i can get away with this!
The parkland/woodland has several gated enclosures (tree plantations, the fencing is to keep deer from stripping the bark from saplings), handy for dog training or letting loose those who need to be leashed otherwise.