Woocommerce checkout throws an error “An account is already registered with your email address”, when you did not log in before checkout.
This is so clumsy. What I want in this case is to immediately show a popup with a login box, with the email address already populated.
It looks a little like this question: Woocommerce: Override login required for existing email. Add order to user account
But it is different.
I can’t find anything that comes close.