My pups were always collar and lead trained before they left me. I fitted a crochet-ed wool collar around each one, last thing at night so they wake up in the morning with no memory of life without a collar. A tag - a couple of inches long - means the litter can pull each other around in play and thus get each other used to being pulled by the neck.
Personally I think 11 - 12 weeks is too late. 9 weeks is fine for pups to leave if they have been properly bomb-proofed by their breeder. The sooner they get into their new routine, the better.
No, you don't want them to walk too far at first at 9 - 10 weeks, but by 11 - 12, they should have been properly trained and manage a reasonable time on the run - but only go out in public after their shots.
I carried Mku in a sling in the woods until he was 'protected', so he could socialise with humans and see and hear other dogs. By the time he could actually run free, he only got one run in the forest and a couple over distant fields before the lock-down was imposed. I carried him from time to time so he didn't run too far.
Now he is restricted to our garden, a neighbour's field or some small woodland areas at the other end of the village. But his recall is excellent and if I do a mile or so (I am restricted too) then he does about 4 at the very least ! It is difficult, but we are managing to meet other dogs, if not their owners, so he is getting some friendly socialising.
He is about 17 weeks now and goes beautifully on the lead but I hate to keep a hunting hound from freedom. To finish his lead training - his breeder had started it with collars - I carried him a distance from the house and let him walk back. Four or five times a day and he was soon walking well.
I can't wait until the forest is opened again and Mku and Hoover can be really free to hunt and race !