More experienced, articulate and knowledgeable people like Broderick Chavez have been ripping holes in these types of bogus claims for years.
Broderick likens it to an elevator. There are levels of development that are largely determined by PED dose, training, nutrition, genetics etc. When this level is reached, more drugs, training, food etc are typically required to reach a higher level.
But as Broderick says, it's not because the drugs stopped working...it's because the drugs
ARE working. And as we know, this adaptation can take a long time.
There like most buildings, there is a penthouse suite, but many lifters are content to reach a lower level and stay there, while maybe occasionally blasting into the 10+ mg/kg bodyweight.
I also think the suggestions regarding T3 should be viewed very cautiously, given that they could have very negative impacts on the heart...