Today the same login serve both the operational customer dashboard and this community forum system.
I see this as a security risk since these two systems are in a very different risk level, hence using the dashboard credential (high risk) for a community forum (low risk) expands the risk for possible live session credential theft from the “low” to be used at the “high”.
Cloudflare runs a bug bounty program with HackerOne. If you can demonstrate a session hijack from the community forum which grants access to the dashboard that would be the place to report it.
My approach is doing things correctly from the start, doing the basics right, and currently, in my view, this design is not secure and should be improved.
If a vulner is found, it is too late.
I guess I’d recommend using a separate Cloudflare account with no zones or data associated if you believe the design to be insecure. It’s unlikely Cloudflare would abandon SSO in favor of an alternative.