Do I really have to suffer through all this parkour in Clair Obscur: Expedition 33 just for another costume?

I already ignored the beach stuff — that was a dumb idea and not worth the time, especially since the reward was just a skin. But now I’ve hit this whole painting parkour section, and I’m wondering… is it also just cosmetic? If so, why make it such a pain? And if there’s actually something useful behind it, is there any way to skip or cheese it? I’m not against using Cheat Engine or whatever to save myself the headache.