Just to be clear, you want to use the combined flow, which enables a user to sign in, or sign up (if they choose too), but instead you want to take them directly to the sign up page?
My question is, what is the user is already signed up? WHy would you want to force them to a page they already have done.
Can you clarify your exact reasons and desires on this?
If you are always going to force them then just use the Sign up flow and redirect them later to the sign in. I don't see why you would use the combined if you plan on forcing them always to the sign up.
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Thank you!
Sincerely, Michael Gernaey