I wasn’t able to taper, and that’s what many people find when they attempt to taper, that the binge happens anyway. It sounds like you may have some people helping monitor and guide you through it, so you may have more success.
Although if you went from 9 to 4 units in 72 hrs that’s a very quick taper. Physiologically your body may just react as if you are quitting in that case, especially if you drank daily.
Anyway, it still gentler on the system to cut back, if you are able to do it successfully.