This is interesting (to me)
I have done a 2 week cycle at 70x2 sprays a day with some great results, but no libido elevation or acne, now I’m doing 10<15 sprays once in the morning and I’m getting libido increase, and some (minor) acne. I’m wondering if 70x2 is too much for me… am I getting the benifits of 4ad and no supression on 1<15 x1 a day, vs. supression at 70x2 ?
That’s odd, I get the same libido effect but with a different end-cycle protocol. During the two weeks “on” at 70 sprays BID, my libido doesn’t elevate at all; however, during the third week where I only apply 7 sprays before bedtime (something Bill R. once recommended), my libido shoots through the roof. I have my own opinion on this regarding T rebound, but I’ll spare everyone from my uneducated theory… 
Nerve cells have membrance associated receptors that bind androgen, which are completely different from the androgen receptor and also not related to at least of of the non-androgen-receptor-mediated mechanisms of muscle growth. What I’m saying is, effect on the CNS (for example, libido) doesn’t have to correlate at all with effect on muscle growth.
Having optimal libido enhancing dose doesn’t mean you have optimal dose for muscle gains.
Androgens can often have a paradoxical effect, as you said, where some increase gives a major libido increase, but increasing yet further gives a decline back only to normal or even below normal sometimes. It varies among individuals.