Here is the blog published by me and my friend Vaibhav Srivastava about GER. Here is his linked profile –  https://www.linkedin.com/in/vaibhav-srivastava-91428716 .

https://us.hitachi-solutions.com/blog/dynamics-365-roadmap-generic-electronic-reporting-tool-in-dynamics-365-for-finance-and-operations/