My opinion only, but I believe Boykins have to be force fetched. FF is tough, as it's uncomfortable for the dog. Once FF is done, the dog (lab, boykin, whatever) should know the pressure goes off if they get the dummy / bird in their mouth. This is the basic principle of running blind retrieves.
You have to find their motivation. Some like food, some like praise, some want to please their handler, some just want to please themselves.
Finding the right motivation, along with just enough pressure to get them to do what YOU want, is the really tough part. Once you figure all of this out, it's easy!
Food can be a great motivation / tool on the early stages, but I believe a force fetched / e collar conditioned dog is the beginning of a well trained hunting partner. From there, Smartworks is a good book system.
BUT, for $5 a month, join the Brown Dog Academy on Patreon. It's hosted by Blaine Tarnecki, who is the premier Boykin trainer in the country....hands down. Even though I had mine professionally trained, I still watch the videos and do drills learned on there. Dozens and dozens of videos. It's absolutely amazing and the best resource out there for Boykins, or anyone that wants to train their own dog.