ok, im hearing you keep 80% of size and strength off of primo... but isnt that just 80% of not much...
when came off my first test p tren a cycle of 12 weeks, i started a "bulking" diet and gained a fairly good amount of muscle... maintained at least 95%+ strength gains... and gained an unsubstantial ammount of bodyfat...
like the OP asked, i was not at my genetic potential obviously if i were able to gain muscle...
however my PCT was very minimal (not reccomended) and i believe what helped keep my strength was the fact that i ate A LOT, got good rest and worked really damn hard in the gym...
not so sure this would work for everyone, but for me, tren srength results are very keepable...