Tbh I think it's fair enough, there's some stretches I feel but overall Sonic can reasonably reach there
Personally I'd scale both Sonic and Super Sonic to tier 2 territories, with Super Sonic being possibly tier 1. Base has Massively FTL+ speeds with possible infinite speed, and Super Sonic has Massively FTL+, likely infinite speeds, and possibly immeasurable speeds via the Solaris fight.
There's also a couple differences I'd make if I were scaling ENG Sonic or JP Sonic somewhat separately. JP Sonic, for example, should have much more solid reasons for resistances to fate manipulation and erasure because Generations' script was unchanged, so all time and space was erased compared to Ian Flynn's rewrite which pretty much just erases areas locally due to the whole "that thing keeps jumping back and forth through time!" And resistance to fate manipulation bc of The End fight, along with the possible resistance of Secret Rings. And I think ENG Sonic would have a little better AP because of the Egg Wizard's English statement of having power beyond what Eggman imagined rather than just holding the existence of parallel dimensions (universes in this case I believe) and The End's infinite statement