BTW, SSG is 3-A not Multi-Galaxy+. The reason Goku is Multi-Galaxy I'm base is because SS is definitely equal to SSG, whereas Goku punching that Sun Blast from Beerus' while not being able to stop it in SS Doesn't make any sense. Further information on SSG, it was clearly shown that these fighters Goku and Beerus were going to indirectly destroy the Universe from the clash of their power alone. They were destroying shit with just Shockwaves. When you think about it, Universal is a low-ball, as to destroy something with just the force from your attack hitting the air or the Shockwaves means that what caused the Shockwaves was much stronger. Just cleaning that up. It's logical to just place him at Universal as SSG, though a likely higher would be warranted if not for the fact that being Universe+ here means something completely different than just raw power. It's, like, complete deletion of the timeline in the universe they destroy as well, right?
Basically, SSG was Universal, period. Goku went to SS1, which, we can assume that Goku's base should be below Universal (Multi-Galaxy+). I would actually argue that Goku was 3-A in SS since the BoG arc, since, you know, Goku didn't get weaker in SS when he lost the form. If we're talking about when base Goku became 3-A, then I agree with RoF, as it looked like it was stated by Krillen or Gohan in those links that Unite my Rice reposted.