The Argument for Dragon Ball: Sparking Zero to Add Non-Canon Super Saiyan 3 Forms

Plenty of transformations will be present in Dragon Ball: Sparking Zero, but the game can do better than just including every established form.
Considered a successor to the Budokai Tenkachi series, Dragon Ball: Sparking! Zero is an in-development arena fighter developed by Spike Chunsoft and published by Namco Bandai.

In Dragon Ball Heros, Jiren said that Gogeta was just as powerful he is, is that true? - Quora

Dragon Ball Z (1989)

Vegeta - The Codex

Official promo image for Super Saiyan 2 Vegeta (Late - Z) : r/tenkaichi4

Does anything in Dragon Ball Super contradict anything in Dragon Ball GT? I know GT isn't officially canon, but is there anything making it impossible to consider GT in someone's head canon?

What is the strongest version of Goku that Super Saiyan Rage Trunks can defeat? - Quora

Dragon Ball Z (1989)

Dragon Ball GT (TV Series 1996–1997) - News - IMDb

Dragon Ball: Sparking Zero's Fusions Are in a Bit of a Pickle

Does anything in Dragon Ball Super contradict anything in Dragon Ball GT? I know GT isn't officially canon, but is there anything making it impossible to consider GT in someone's head canon?

Spike Chunsoft

Dragon Ball: All Main Characters From Weakest To Strongest, Officially Ranked