Guardian MFA, Custom domains and blocking 3. party cookies

Maybe its me who can’t find the documentation or the setting, but i can’t get Guardian MFA,custom domains and blocking 3 party cookies to work.

Blocking 3. party cookies is required - we can’t ask our users to allow 3. party cookies and we can’t ask them not to use MFA.

So with that said here is the problem:

When enabling a custom domain, the login happens on login.ourdomain.com - all good so far.
But the mfa-widget-1.5.js apparently connects to ourauth0domain.guardian.com and something then sets a cookie there with the domain ourauth0domain.guardian.com. This is obviously blocked because it is a third party cookie (originating from an root domain different from our login domain)

So did i miss a configuration, a section of the documentation that states, that MFA, custom domains and third party cookies are a show stopper or is the system just plain broken because no one considered this scenario?

Can anyone shed some light on the issue?

Edit: Ok, so after a little fiddeling i realized i can change this
" mfaServerUrl: “{{ mfaServerUrl }}”,"
to this "mfaServerUrl: “https://logintest.ourdomain.com/guardian/” in the Guardian Multifactor hosted page.

So where in the documentation does it state that you have to do this to get custom domains, MFA an TPC to work?

Thanks Thornton this was helpful. It’s frustrating that we need to use a custom Guardian MFA hosted page to support custom domains in Auth0. Seems like a feature that should be supported by the hosted page without having to now maintain a custom MFA hosted page.