I think Super Forms should have Acausality Type 4 anyways, but with reasoning that's not yet on the profile.
For context, Frontiers takes a new approach with the canon by making the ENG and JP scripts equal in canonicity (in other words, one version doesn't take priority over the other), simply altering the JP script to better-suit the JP audience. This is accepted already but I just wanna re-clarify. Thanks to
@JJSliderman for providing the scans for this.
For starters, Sage says Sonic is attempting to transcend causality.
As per
the intelligence section of her profile, she is a very literal character that relies upon calculations that she can do by the millions. We also know this isn't hyperbolic use of causality because of Tails' mention of causality when referring to the forcefield surrounding the Starfall Islands in the beginning of the game.
Prior to battling The End, Sonic says "he'll break the chains of fate".
Here, The End says it's attunement is ruling fate on everything in the universe.
The End states it's been this way since time immemorial, claiming there's no way to challenge it.
And of course, The End states Sonic's actions transcend law and time.
https://i.imgur.com/NkI0VLH.jpeg
While Base Sonic ultimately succumbed to the Corruption that plagued him, Super Sonic and Sage within Supreme (each of the Titans are fueled by the Chaos Emeralds, meaning Supreme's participation in the fight isn't contradictory) ultimately defeated it. The way The End addresses Sonic through its dialogue is something I believe to be the clearest evidence of Acausality Type 4 for Supers.