update: this specific issue is something I could work around differently: defining a user that has its own credentials within SF who can be used in the auth flo

update: this specific issue is something I could work around differently: defining a user that has its own credentials within SF who can be used in the auth flow did the trick without any redirect needs! See: https://gist.github.com/Anonyfox/3f36c26fb00a9bc4067d6dc9c9a87137 https://gist.github.com/Anonyfox/3f36c26fb00a9bc4067d6dc9c9a... I sound totally dumb now to bitch about it, but glad I could solve it in like 1 hour in a sufficient way