Covering Trex Enhance Board Ends
The 2 choices you suggested are pretty much the standard. The amount of overhang for the first choice can be varied, from a 1/2" to 1", perhaps as much as 1 1/4" AFTER the fascia is applied. This will require screws through the top to help keep it in place.

There is no reason the second choice will not work either, it give a more contemporary/modern look that may or may not fit your exterior of your home. The other is more traditional. The fascia board will need to be wider for the second choice, to cover the framing the same as the first choice.

If it was me in either case, I would router the cut ends and edges the same radius as the  uncut factory edges, so all the gaps take on the same look.