This sounds great for softening roots... but at the end you said to use it after bleaching? If one was to use only this on the roots, and it works in 5 minutes, that would be problematic. As you said, we'll need to be careful not to touch adjacent pre lightened hair, but that careful application takes more than 5 minutes to do the whole head. Does this mean that the areas it is applied to first will suffer more damage and lightning due to the fast processing time? That would give a very uneven result. Thank you.