I also had pubertal gyno and ATM running aromasin at 12.5mg ED on ~1g of test/0.42g of Win per week, everything is going/feeling great. Even with a mild cycle like so I would take the percussion if you know you're estrogen prone.
Half-life of anastrozole is ~50 hours, hence it is often taken EOD; a common dose for arimidex is 0.5mg EOD. To keep levels steady you could go with 0.25mg ED, I might just take 1-2 days off in the middle of the week to let the levels drop back down otherwise you might build up too much overlap and be overkilling with the AI (symptoms of low estro include: Decrease in libido, anxiety, fatigue, depression, achy joints, pale skin, etc). Also if you really think it could be a problem you could get some letro just to have on hand.
Also just clarifying: you're saying you developed gyno during puberty and still have it, correct? I don't know your current body composition, or severity of the gyno but I can tell you my man boobs have subsided with time/training, though it could be my issue was mild in comparison. I believe the only thing that is "irreversible" are if tumors have developed; Obviously the cause of gyno is increased estrogen activity in breast tissue, once your body gets over the aromitizing issue (which will increase as you become more fit) and estrogen activity in breast tissue has subsided so will the breast tissue.
Taken from the mayoclinic:
- Gynecomastia during puberty. Gynecomastia caused by hormone changes during puberty is relatively common. In most cases, the swollen breast tissue will go away without treatment within six months to two years.
Think about women who get ripped, their bust size decreases and they still have significant estrogen. You're a male, as you're test levels increase/stop aromatizing at a high rate you won't have anything promoting those female sex traits.
Hope that helped, best of health!