As someone said - it's likely not such a big problem since the trees are going dormant then anyway.
I grow all my garden in the midst of a 50+ yr. old forest (very tall pines, oaks, madrones, fir trees) and nothing gets more than about 3 hrs. of sun a day in summer (some get nothing in winter because of a big hill to the south). I get wonderful
apple crops, and Italian prune, asian pear, cherry, everbearing Illinois Mulberry, and fig crops. I planted english walnut, filberts, paw paws and a persimmon that have not gotten old
enough to bear but are looking great. Some things have taken a long time to start fruiting - like two of the first apples I planted - took 7 yrs. but now give me wonderful crops. I have pomegranate, and hardy kiwis that are now starting to bear well, and grapes that bear well -but took 7 years to get started.
I just try stuff. Blueberries are my biggest disappointment - only the Sunshine Blue variety will give me any fruit to speak of. They must just need a lot of sun to bear. But I can't tell you all the 100's of types of plants I grow that experts say need "Full Sun" - that do just fine here. Some may not bear as well (or as young) as they would in full sun - but they do just fine. They give me "enough".... :-)