Microsoft Lists - Best Practice Approach?

I have the following scenario I am trying to set up;

1. I have a MASTER List which provides Critical Due Date information which I am looking to give an external Agency real-time access to.

2. The MASTER List currently resides in a Sharepoint Teams Site (which is managed by the team). The List effectively flags up when work needs to be done based on the Critical Date column (30 days ahead of the Due Date). All works fine.

3. I want to give the Agents access to a view on that list configured to provide them with key information (but not all information) on that list via an Agent page on a Communication Site. The Agent Communication Site is associated (in a Hub relationship) with the Team Site.

4. When I try (by using the Webpart to add a view to the MASTER List) I am unable to choose the List as it exists in the Team site only. I have been advised previously that I can set up an exact copy of the MASTER List from the Team site and locate it in the Communication site, but keeping the two in sync (even using a automated Flow, is proving problematic), is there now way I can give a Communication Site  direct access to a List View? This seems such a fundamental requirement that I find it a little strange that  an easy 'out of the box' solution to this dilemma is not available?

Or am I missing something very obvious?

I don't want to give Agents (external to the company) access to anything other than a fixed view of the list - which I can easily do, if I can give them limited access to the List, but this option does not seem to be available without creating a new List. Is this correct?

The Agents are authorised via our Azure AD as Guests accounts - with a security group of Agents to give them access to the Agents Communication Site.

These seems such a common user case scenario - what is the Microsoft 'Best Practice' approach to addressing such an issue?

Thanks,

c.