Wow… you’re really fast… Does improvements actually come that quickly even at such high level as you? (I mean, 11.4 is already a really good number)
I personally think I know basics about arm swing and steps, but I have much to improve on starts and being relaxed (or not co-contracting agonists and antagonists). I could also fix the timing of switching from acceleration to top speed.
I wouldn’t be able to advice you at this point, since you’re waaaaaay better than me right now.