Personally...or for others? For myself, I haven't used anything for over 6 months...but when using that combo I usually run 250-300 mg of test/week, 20mg trest ace/EOD, and 20 mg tren/EOD. But...when I go back on (soon), I am likely going to cut the tren entirely and keep everything else the same. I like tren (at low doses), but I'm not trying to push things anymore. I turned 44 the other day and am at the point where I need to be transitioning away from focusing as much on size and strength. From here, I can see the end of the road...and it's not that far away. So, my focus will gradually move more towards optimizing my diet for the purpose of cancer and neurodegeneration avoidance, while slowly reducing bodyweight as the years go by. I can see myself staying around 240-250 lbs until age 50, taking it down into the 220's in my 50's and then, by age 60, keeping it at no more than about 200 pounds.
For others? Dosage should always be determined by goals, personal response and the willingness to assume risk.