Since I was the one who originally made the Low 1-C upgrade in the first place, and got it passed, I’ll clarify the Hoopa part.
Hoopas part of the justification is only supposed to be minor support evidence to add onto the stronger more significant evidence in the justification. It’s not a main justification for Low 1-C, just an “add on” point.
But Hoopa was added in because in Clash of Ages, Hoopas rings (which effect space-time) possess infinite power. Hoopa in his strongest form, Hoopa Unbound, was able to forcibly have his rings connect to the dimensions of the Creation Trio and summon them forth. That means the power of Hoopas rings can, by force, interact with 4-D space.
However, even as Hoopa Unbound, it can’t interact with or in any way connect with Arceus’s dimension, since Ghris, a human with a small figment of Arceus’s power, was able to weaken Hoopa by sealing his power away, and put restrictions on what his rings can do. If a small figment of Arceus’s power is > Hoopas rings power, then it gives a good implication that Arceus’s dimension is superior over what can interact with 4-D space. And the only realistic way that could happen is if Arceus’s dimension is 5-D (which ties into the other stronger evidences for Low 1-C)
Hoopas part of the justification gives a small implication of Low 1-C that’s just “worth noting”. It’s nothing more than an add on for the other complied evidences.