Are you satisfied with your windows? If not, do not cover the trim. That way
in the future you can replace the window without removing the siding.
If you are OK with your windows, do what ever looks best.
Good way to see the contractors work, is to ask to look at what they have
already installed.
That way, you man or may not even notice the things you are asking about.
my2cents.

The few examples of this I have seen did not look so good. I could see the
mitre joint in the aluminum. Also, if I get the fascia wrapped, one
contractor said it might not look good because of the size ( 1x10) would
cause some waviness.