you won't need Letro on 500mg of test . especially when your running an AI daily . to put it in perspective , I have cruised on 250-500mg of test as my TRT (also 200mg test with 500eq) and take my AI 2x per week is all at low dose.. 500mg of test with no other estrogenic compounds is all your doing, you really don't need to be that aggressive with estrogen control (unless your prepping for a bodybuilding show and need E crashed).
I'm still a fan of Letro, and have it on hand and use it quite often (though don't recommend it for beginners). theres a big difference from a beginner using it with only 500 mg of test , and someone needing it cause they run 1gram of test with 700mg of dbol and 350mg of ment . with that type of bulk shit can get out of hand and Letro is awesome . only 500mg of test though with nothing more, I don't even check and see how much AI I have left , let alone Letro.
also just cause a drug has a short half life does not mean you have to dose it daily . dose it to accomplish the needed goal . Aromasin will inhibit aromatization for days after taking it , you don't "have to" maintain steady blood levels of it consistently to work it does its job when its active and you don't need it active 24/7 . also keep in mind if a drugs half life is 2 days , it means its still working and in your system to some degree for 4 days
your use of proviron for "hardening" , yet you question wither proviron has anti-estrogenic effects or not . LOL , how else in the world would proviron give any 'hardening' effects without being anti-estrogenic !!? its not anabolic , so the only capacity it has at muscle hardening is drying you out through anti estrogen effects or binding shbg and letting other hardening compounds work better .
sorry long post , just trying to help you out though