Glad to be here!
Hmm. Flexbox. So, honestly, I lost track of the differences in the implementations of Flexbox. I do remember the time that Firefox had one implementation and other browsers had another and it was a bit of a faff to get it right, but those days seemed to have long passed.
Honestly though, I know I want to use Flexbox a lot more, but I always get burnt on the syntax (and I rarely get it to flex the way I want first time around). It's because I don't use it day-to-day (like I do JavaScript), most of the CSS I write, I'll write and then move on and forget about it.
So, to answer: yes, but ¯\_(ツ)_/¯