I am one of those people who had FFS early. In fact, I had a feminizing rhinoplasty even before I started HRT. I was also already presenting as female part-time before my rhinoplasty.
About a month after my rhinoplasty, I started HRT. And then about 4 months after starting HRT, I went full-time. And then about 3 months after that, I did the rest of my FFS (which included brow bossing reduction, brow lift, trachea shave, and blepharoplasty). Note that I didn't do anything to my chin or jaw. For one thing, my jaw wasn't that pronounced to begin with. And secondly, I figured that with more time on HRT, the masseter muscle reduction would soften my jaw as well. I left open the possibility of going back for additional FFS to my chin or jaw if I later felt I needed it. So far, I don't think I do.
So it's really up to you how and when you want to do FFS. I do agree that it's generally better to wait a year or more after starting HRT. But as you can see in my case, I did things differently and in stages. The downside to doing FFS in multiple stages is that it ends up costing a
lot more. And you have to take more time off work to recover from each surgery. But it worked out ok for me, and I'm glad I did it this way. I probably wouldn't recommend it for most people though.