tren acetate dose ~ 85% of tren enanthate dose
75ed tren ace = 75 x7 = 525 mg ew tren ace
tren enan = tren ace / .85 = 525/.85 ~ 600ew tren enan
600 ew tren enan will basically equal the tren delivered by daily homebrew. So, less than 600 is illogical and likely to be disappointing to you. I would say start at 600ew. Because most tren enan is 125 or 250mg/ml, I would go with 750ew tren enan if you found your tren homebrew a comfortable cycle.
I have this information and more in an old post on tren esters if you need the link. Tren enan is a godly cutter, I like it much better than homebrew/tren ace for some reason.