> It is estimated that Jupiter is essentially the largest any gas giant can get
That does not appear to be the case if we mean mass, not diameter.
But... he literally said in the following sentence that adding more mass does not change size, implying that he is talking about diameter, not mass.
Who uses the word size to mean mass? The typical colloquial analogue to mass is "weight" - which nobody would ever conflate with "size".
Yes; I was under the impression that from context it was clear what I was talking about. In astrophysics, to avoid precisely this confusion, the convention is to use the adjective 'massive' when comparing, well, masses, and 'largest'/'smallest' for the dimension of length and its higher powers (radius/diameter/area/volume). For instance:
> the Sun is 3.33e5 as massive as Earth.