There is a limit on the bodies ability to do anything. 20 lbs in a year maybe. Actually muscle gains. It will take some amount of fat gain.
Adding 20lbs on a cycle with certain steroids is completely possibly but its not real gains.
I went onto TRT and started to lift seriously. Fitness pal said for my height amd weight to eat like 2600 calories per day. I just kept eating more and more. Once I started to see a loss in definition the scale went up. When it quit going up 2 weeks in a row I ate more.
I started about 135lbs, single digit fat, low test, elevated estrogen and not eating. My actual weight was the mid to high 150s. Possibly 160s sometimes.
I went on 200mg wk test cyp, trained hard and was eating about 3500 calories per day. 20 wks with a gain of almost 30lbs.
I'm epileptic and have issues related medications is why I was so skinny amd had low T.
Now about a year later I'm on 120mg wk, no lifting and sitting at about the same weight with less definition but no working out due to epilepsy.
Maybe the sudden shock of eating, liftong and higher test let me gain about 15lbs. But it's certainly not normal. I've kept the weight.
If you can see your abs you're probably not eating enough. Steroids increase muscle making potential. Like hiring extra workers. If you dont provide more supplies (food) nothing is getting built.
I didnt even eat "good". Lunch meat sandwiches, peanut butter sandwiches with like 6 tablespoons of peanutbutter, dinner left overs and huge dinners. All I cared about was making calories and everything I ate had protien.