More annoying is the fact the anime didn't go with the obvious idea that the manga has, which is Vegeta learning how to use SSGRed which shows he can learn mastery of forms, which is why he got ascended SSGBlue.I don't find Goku being able to access it again odd, the odd thing for me is that Vegeta can use a form higher than it without the ritual with literally no explanation as to how he did it.
That, is in fact, poor writing.
In the Vegeta V Hit match Whiss reveals that going SSGBlue burns stamina on start up which is how Hit beat Vegeta. But in this tournament Goku keeps going to the well over and over.Oh yeah hes dark blue hair deal was a major fan service ass pull. And the way he just kept getting up after "Using all his stamina" OH WAIT HES GOT MORE BLUE!
In fact the only time you see Goku struggle at all is at the end when his hair flicks between gold and black when they are making the final push V Jiren.