You're leaving gains on the table at any dose, but...
This is very much a rough spitball, but you're probably not leaving too much on the table up to about 250mg, some guys (mostly younger guys but some older depending on response) can probably get away with secretagogues up to that point and beyond, as you get towards 500mg that gets iffy and probably where I'd say GH becomes a must have, IMO.
It's absolutely far below 3 grams for sure!
Since most guys find a huge benefit (not necessarily hypertrophy related) from low doses of GH at TRT or TRT+ levels of AAS, this tends to be a moot point, but there you go.