While using CDS (current environment) connector for the Regarding property which is separately listed for each entity would you assume it’s unnecessarily to prefix a dynamic property value with a type ?
Well, unfortunately, you have to. The same way as for other lookups, you have to specify type prior the dynamic property. In my case it looks like this:
/accounts(dynamic property)

Read this article below to learn more about CDS (current environment) connector: https://saralagerquist.com/2019/12/15/cds-vs-cds-what-connector-should-i-use-in-power-automate/