@dan Yes, I am using the login API and the Identity Provided API. More specifically, the following routes: /api/login & /api/identity-provider/login. They both have similar response cookie functionality. Your explanation makes sense, however I do agree with the GitHub issue about this functionality being optional (or at least allow the developer to choose which response cookies they want to set). For the meantime, I suppose I'll just use the provided functionality as-is and look more into the mentioned alternatives if necessary.
Also, thanks for linking to the SameSite configuration. I'll take a look at it to see if it fits my needs.

Thank you for your reply!