When to trim?

I know some trim and some do not. If you are a person that defoliates when do you recommend? Currently have a plant in flowering and I was thinking about it because of some of the buds on the main stem look to be covered. Are the fan leaves still needed at this stage?

Hey dude, as an example look at a tree. A lot of its leaves are under the canopy in the shade, under the tree there's a variety of plants that live in permanent shade.

Light is important, but the leaves on the plant are equally important, even those in the shade serve a purpose and make use of refracted light.
Contrary to opinion the bud itself doesn't need direct light, all the energy is distributed as needed. Look at a lot of plants, runner beans, chillies for example, a lot of the fruit n veg will actually grow in moderate shade yet as long as the plant has overall enough light and nutrients there's not a problem.