[Feature Request] Allow Dataspace Use in Relationship Rules

It seems that Regular Custom Rules allow the use of Data Spaces, but not for Relationship Rules, it is not a selectable option even if the object is linked in Relationship Configuration.

What Regular Rules Get:

What Relationship Rules Get:

A use case would be the Call to Action Object which has a lookup to Relationship. I was working with a customer to control CTAs being fired and they need to pull a detail from Relationship Detail to filter by.

The workaround seems to be creation of SFDC Cross-object formula, which for some organization needs approval to make.