Well not sure I explained it well enough. The thing is that if you just picked blueberry and 1 strain and crossed it and made 1000 seeds. You could plant every seed and possibly not have 2 plants that are the same and any of these fantastic plants that come out of it are going to be a clone only thing unless you spend the time to stabalize the things your looking for and thats not nessesarly easy.
I suppose that if your just looking to throw the dice and see what grows then crossing it with many other strains would work. The only thing is that if you plant that seed and get a fantastic plant you will want to keep a mother of it so that you can clone the thing, because planting more of that same seed does by no means garantee you will get that same fantastic phenotype you got with the 1st one.
Keeping a clone mom and dad alive during the entire process for back crossing is a must if your looking to stabalize certian aspects of a crossed plant strain. If your going to do multiple crosses and save the best of each cross as a "clone only strain" that would be an option. However if your like how this strain grows and how another one tastes to get there offspring to possess both of these qualitys is not an easy thing and will require multiple back crosses to get the desired results and there is still a chance you dont even get those results at all.
edited to add this link:
https://www.rollitup.org/general-marijuana-growing/173816-breeding-seeds.html