I'd fully stand by the idea they're semi-relevant to their higher levels of power.
The biggest piece of evidence would be that SSJ Goku is shown to be able to physically compete with Hit's initial self and Beerus saying Goku's supposed to be stronger, and it seems doubtful he was factoring in Goku's higher forms when he could've just said so. In turn, the gap between Initial Hit and Less than 10% SSB Vegeta has to be less than that between SSG and SSB for Hit's Time Skip to have worked, and that gap in itself is something not too great in power or speed when SSG Vegeta could still react to Black in time to switch to Blue instantaneously when necessary.
The next piece of evidence is the fact SSG Goku felt a need to dodge Zamasu's telekinesis at all despite Shin barely being able to hold SS2 Gohan in place a few seconds, and we can't say something such as "Zamasu's telekinesis is far better in general" when that's not suggested to be the case at all. That said, the gap between SSG Goku and someone weaker than his SS3 self is suggested to be lower than that between Shin and SS2 Gohan, which even at its largest is still dwarfed by the gap between Z's Solar System level top tiers and guys that could destroy the U7 macrocosm in not too much time against a comparable opponent.
That, and most of the counter evidence tends to have little weight behind it. Things such as Trunks being compared to Gohan require remembering that Trunks had no better benchmark (A Boo that was never released and who Goku would be unaware of how much intel Shin was able to give being vague at best) and most of the relevance given to Boo Arc characters in the current arc is very contradictive on its own with things like a non-God Ki Dai Kaioshin Boo outperforming SSG tiers.