my 4 month old border collie is starting to herd the kids and the broom and im genuinely not sure if i should redirect it now or let the genetics play out, looking for people who chose either path and can say which they would choose again

Kade is 16 weeks, red merle, from a working line breeder in idaho who places into both sport homes and pet homes. We are a pet home with two kids (6 and 9) and i was honest with the breeder about that and she still placed us because the parents on her mom side are more "biddable working line" than "high intensity working line" (her words). So far the dog has been a delight. Smart, food motivated, sleeps through the night, mostly housetrained, neutral with strangers, recovers fast from any startle.

The thing that started two weeks ago. He has begun crouching and stalking, which i can see is the herding eye starting to develop. At first it was funny and only with toys. Then he did it with our 6 year old when she ran across the kitchen. Last week he started circling and trying to redirect our 9 year old when he was riding his scooter in the driveway, and yesterday morning he was actually nipping at his ankles, not aggressively, but with intent. I separated them, the kids understood, no one was hurt, but i watched him afterward and he was visibly frustrated that he did not get to finish whatever he was trying to finish. He has also started "herding" the broom when i sweep, which i had been letting him do because it felt harmless.

I am hearing two completely different things from people. Camp one (mostly youtube and pet dog trainers) says redirect the herding behavior every time, do not let him practice it, channel it into fetch and flirt pole, and you can largely live with a border collie who does not express herding behavior at home. Camp two (the breeder herself, and a working line forum i lurk on) says the herding instinct is who he is, suppressing it does not work long term, what i need to do is teach him appropriate contexts (livestock or herding ball sport or treibball) and clear off switches in the house. The breeder specifically said "the dogs that wash out of pet homes are the ones whose owners tried to make them not be border collies, not the ones who were given somewhere to do the thing."

So my actual questions. one, for border collie owners whose dogs are now 2 to 6 years old and well integrated into pet life, looking back did you redirect the herding behavior at this age or did you channel it, and what would you do differently. two, the kids piece is the part i am most worried about, did your border collie outgrow the nipping at moving children or did you have to train through it specifically, and how long did that take. three, is treibball or herding balls (which i can do at home, no livestock required) actually a meaningful outlet or is it pet owner cope, because the working line forum people seem to think it is real and the pet trainers seem to think it is mostly cosmetic. four, at what age does a border collie in a pet home actually have a calm off switch in the house, im starting to understand that 4 months is way too early to expect it but i want a realistic timeline so i know what im working toward