I have been using the mod for 2 days now. Used it on Memorial Arena and Abyss but I still haven't got banned. Tried using it on Elysian Realm Finality, still not banned. Tried it on Universal Mirage on single player still not banned. I think it's about using the mods in subtlety and do not stand out. If for some reason you became a top MA with undergeared valks, it's suspicious enough to get you reported. And I think devs only ban players who display suspicious progress. Do not use it on Coop stages and ranked modes.
I will still monitor if I get banned tomorrow since it will be end cycle. If I get banned, I'll let everyone know.