Items to Consider
If you stick with the current plan, you will almost certainly be flying a PMCO 772 with a very good (if not totally perfect) lie-flat seat, and excellent PMCO-style catering. Make sure you assign yourself a middle aisle so nobody crawls over you.
And you will spending fewer miles.
If you go for Global First, you will be flying a PMUA 744 or 772, with a slightly longer lie-flat seat with catering perhaps somewhat better, perhaps somewhat worse, depending on whom you ask.
OK.
But then, once you get to SFO, you go through immigration and customs, sit around and then pile yourself in a domestic mid-con to finish your journey, with mediocre meal service and 38" seat pitch.
Also, you will be adding about four or more hours to your trip.
So, you trip will be longer (with a potential for delays and a missed connection), you will do the last 4 hours in domestic FC.
And for this you owe them more miles?
Doesn't seem remotely worth it to me.