Prepared dogs? I meant pure bred dogs, of course.
I think the biggest problem is in-breeding...it increases predictability but at the same time, reduces genetic diversity. Over time, that leads to all kinds of health problems and need for even more and more rigorous selection for breeding which then further reduces genetic diversity, especially with recessive genes.
It doesn't matter where it is pure breed, designer cross breed or a mongrel, it is the inbreeding which IMO, is the issue.
The thing is you are most likely to have extensive inbreeding for pure bred dogs, simply because predictability and conformity to certain breed characteristics is so important.
Not so much for designer doodles, although that could happen two-three generations down the line.
Least likely with mutts, as there is no monetary value to them, so who on earth would inbreed a line of mutts? Could happen by accident, but would imagine it is a very low incidence, as compared to purebred dogs.
A long way of saying there is no unambiguously good way of breeding and op should go ahead and get the puppy she wants. But might be a good idea to look at a doodle rescue. You probably won't get a worse (or better) dog than directly from a breeder.