i desperately need more granularity on playback speed

I often make sped up gifs (as snippets of demo videos). My preferred speed is always somewhere between 8 and 16, but i dont have an option to select anything between 8 and 16, which are far apart in terms of speed. Especially for gifs its important, because i need to get to the 10 seconds exact (because longer is not supported on many platforms when posting)

THANK YOU