@ryanshah112 and @river - FYI - when I started this thread I had a hard requirement to use Webflow. Memberstack was really the only viable option for SSO via OpenID and I have not looked at it in maybe 6 months so some things may have improved there. But if you are willing to consider Wordpress there are a lot of benefits with DiscourseConnect.
Ryan - I started with the Business plan in order to test it out but I switched to Self hosted after a couple months because I really did not need “business” level packaging / features for my POC other than OpenID. Depending on what you need you might want to consider that and I recommend @pfaffman if you need help setting that up. Super easy.