Just saw your original thread. I think all working breeds are better when you buy working stock. Whether Labs, Cockers or springers. They are simply better allround.
A friend got into breeding and had a really good female that she bred from. They are only allowed to register 2 litters then after that any litters are not pedigree apparently. She got a singleton first which you neve sell and that male is a real good specimen. She has studded that lad out as the mother was from one of the best lines and the stud used for here was similar. So now that dog is in demand from other breeders. A money earner too. It is always good to get the good scores for the health markers that are checked and recorded. A clear for most of them from both parents and you get a clear line from then.
Anyway the female she had has had her full quota of litters and is now retired. The male is a beast with muscles on muscles. A good instinct for shoots too. They have friends who own a shooting company and they took him to the shoots. He was virtually there from day one for that kind of job but they took him to get trained by IIRC a Scottish breeder who trains top field champs. Not sure they compete as lost contact.
Labs are perfect for companions and emotional support dogs are amazing in what they can do. Have you ever thought about looking into training your new lab as an emotional support dog for miniD? Your previous might have had it instinctively but does the new pup (now full grown it looks)?
Sorry if you have already talked about this earlier. I am late to the thread and cannot read it all I am afraid.