Any way to disable a Magran's Fire challenge during a playthrough?

Topic. A little odd you can change all other difficulty options but the Magran's Fire challenges (or maybe I missed it?). Didn't realize how much I'd hate Wael's challenge, would really like to turn off so I don't have to restart...

I feel the same way about Hylea Challenge (but that's because Vela is bugged right now).

Pretty sure there's no way. Maybe with the console, but I've never seen such a function, also no way to add bereth's blessings as far as I know.

I would be interested in vice versa - adding new challenges mid-game (like Ondra's and Rymgrand's). Is that impossible too?