It's a thorny issue - but Tesla will not downgrade a release so you need FSD to catch-up with your release number.
Has your car receieved a new SW release? I just recently got the FSD (as I was waiting for the camera update for my 2017 S). While I was in the FSD queue my car wouldn't update to new SW releases that was ahead of FSD. It kinda waited until FSD passed my build number and then gave me a couple of SW updates really late. So I thought the Tesla SW automatically stopped you from updating when you entered the FSD queue.
I would also guess that the wide release of FSD-11.x will merge in all current SW updates - but it's hard to know. I'm kinda hoping that they make a december surprise release for us FSD owners as well.
And to be honest FSD is currently somwhere beteen a gadget and a useful feature. More towards the gadget side. I really like using it and it's rare that it's actually dangerous (in my experience)- but it's not a comfortable ride and it's so timid that it gets VERY frustrating.
