Also, Ant is incorrect, as he occasionally tends to be.
Marvel/DC crossovers were at the time treated to be canonical to both DC and Marvel, falling under our
canon crossovers. However, that might have changed with time. That being said, I am fairly sure Marvel still treats it as something that has happened, with Brothers and their respective "Megaverse' both appearing as late as in 2023, and having a cameo in this year's DC/Marvel.
So, I doubt you can still prove it as canon for DC. But even with Marvel, it becomes
onesided crossover. So, Doctor Strangefate scales from good ol' Doc Strange fully (what he had at the time I mean), and from what Doctor Fate showed in the crossover itself