Yes, it is possible using our Shopify SSO app. When a user SSOs into your Shopify store for the first time, a newUser tag is assigned to the user in the Shopify user field. The User user tag will be removed when the user SSOs for the second time.
We can get on a call to discuss your user case. If that works for you, let me know your availability and time zone for the same. You can contact us at shopifysupport@xecurify.com.
Looking forward to hearing from you.
Thanks & Regards,