Your mangoes look wonderful.
This is only my first year getting fruit from my PTN-1 mango tree. The fruits are still green, I fertilize the tree heavily with chicken manure and organic citrus fertilizer, plus fish emulsion once a week. The tree is flushing a lot of new growth while still holding the fruits.
I am planning to pick all the fruits in 2 weeks and just let them rippening off the tree if they are still green.