Cannot configure tunnel for Custom Hostnames (by Cloudflare for SaaS)

I am trying to add a Custom Hostname as a public hostname for Cloudflare Tunnel. The Custom Hostname has been successfully set up within the Cloudflare for SaaS.
However, the Cloudflare tunnel web GUI does not allow me to add it as a domain.

As a result, I have following problems:

  • The chatch-all rule is applicable for a Custom Hostname, resulting in the loss of the granular control
  • Cloudflare Access cannot be configured on Custom Hostname

Are there any options which can deal with the issue?

I have found a related positng, which points the situation:

Hoever, it seems like a flaw that a Custom Hostname cannot be protected with the Access.