The only thing I'd say is depending n the breed there may be other issues that are not a problem for non shooting dogs but could be a problem for working dogs.
Things like noise/whining possibly even gun shyness or dislike of water potetially could be more if an issue from non working parents, althou that brings on the whole nature versus nurture debate. If u believe they can be genetic.
In a lot of cases if u put the ground work in and introduce them correctly u shouldn't have a problem, good handlers never have gun/water shy dogs no matter wot breed
Also the fact now many owners haven't a clue how good or bad there bitch is, so rubbish bitches with major faults are breed with.
So really in some cases the 'working' title might not mean an awful lot.
Wot are u training the dog to do??
Personally if ur just wanting it as a gundog to fill a roll similar to ur cockers I'd just train ur dog in a similar fashion. A wee bit fine tuning here and there to suit ur dogs personality.
I'm about to have a go at training an hpr with placeboards, never heard of anyone doing it before. But in theory can see the benefits.
End of day most dogs have similar ish psychology many things that work with 1 breed will work with another.
Just have to adapt as u go to suit ur dog/breed
I always liked Micheal branders books more, althou I have to say not a lot in them that's not in other better written gundog books.
Very little deer/scent training written in the books.
I always mind years ago sitting in a shoot howf a with a local legendary trainer/trialler who's won everything and got the t shirt.
He was talking about his 1st Ftch he made up, said vet phoned him he had a healthy but wild dog in to be PTS, he took it away and made it into a Ftch.
Granted that would off been in 70s doubt u could do that now as standards a lot higher