Remember Identity Provider on logout
When a user logs out after signing in with an external IdP, the logout screen offers a "Remember the Identity Provider?" checkbox so the same IdP is preselected next time.

The logout screen includes a "Remember the Identity Provider?" checkbox. If checked, GIP stores the chosen IdP for that browser session so the same IdP is preselected on the next login screen, simplifying subsequent sign-ins.
If unchecked, no IdP preference is saved and you must choose an IdP at next login.