I always allow the age of the tree dictate the how much fruit I will allow it to bear.
New Cutting-0
1 + year old- maybe 6 to 9 depending on size
2+ year old- 12 to 15
3 + year old 20 to 25 maybe as high as 30
4 + and after- whatever it can put out
Once 5 years old it seems to reach it full potential in terms of flavor. The cutting or newly formed tree, needs to put energy into growing properly. If energy is put into BOTH the tree and fruit, it will produce itself to death.
I had trees last year in there 2nd year. I pinched off half and had only about 9. But they grew big and delicious. They were flavorful and well worth it. Its not about the number. You can have 15 fruits half sized and bland. Or you can have 7 that are large and bursting with flavor.
Also getting rid of the breba in the first few years can help develop more tree growth and earlier Mains that have good flavor.