I don’t know but I have some theories. I’ve found my E2 to be somewhat “sticky” going down. My ratio seems to improve if TT goes lower(E2 does as well but not linearly I don’t think) but I haven’t done enough testing to prove this.
Also there was a guy who used to post here name Prisoner who claimed that your HPTA starts kicking in at low doses of exogenous T. If that’s true than maybe I’m getting some of that intratesticular conversion to E2 that is also improving my ratio.
Here is a thread he wrote about tapering but it has, in my mind, some relevance for us.