Another question about how to add custom columns to the AEM Inbox

I want to add two new columns to the AEM Inbox: Content Path and Initiator. I've read through a lot of inbox questions here on Experience League, but I am still confused on how to do this.
This question basically reflects what I want to accomplish. It is marked as solved, but the solution is another post by the OP that links to an AEM Forms solution. Is the AEM Forms doc really the correct solution for what I'm trying to accomplish in regular AEM? If so, am I supposed to create two services for both Content Path and Initiator? Both of these values are part of the Workflow Info tab so I assumed these values are already exposed somehow?