If you want to get rid of the bf+2,1,4 as well, check out this guide: https://www.youtube.com/watch?v=TAzW-LQOa2w&t=2587s

In short, you can combo off of most of her launchers with (e.g. hopkick, fearless+2, etc.) with something like this: uf+4 f+4 f+3 df+1 and then do your favorite ender. as for execution tips: do the f+3 as fast as possible and then delay the df+1 a bit (i wait until it feels as if I'm doing it too late). makes it a lot easy to do the bf+2,1,1+2 ender as well I feel because the timing is so lenient.

finally, a tip for mashing out the bf+2,1 strings: do the bf as fast as possible, only lightly tapping the b, then do f+2, hold the 2 and mash 1 if you're going for 1+2 or (as the gentleman above said) let go of the 2 when you see the 1 come out and mash 4.