Handle scenario: account created through IdP but still allow sign-up

Getting advice
1

KC handles the case:

  1. User signed up through KC
  2. User logs in through external IdP → allow linking account

Why is the opposite:

  1. User logs in through external IdP → account is created
  2. User attempts signing up through KC without IdP. → Error “mail already taken”

not handled. Are there any particular reasons?

Our use case is that we allow onboarding users by way of IdPs but do not want to block them from signing up with a “native” account.

Thank you,

David