it looks to be still working as long as you stay in text mode. So the standard UI no longer works but the text mode still will.   (I took the example from this link: https://experienceleague.adobe.com/en/docs/workfront/using/reporting/reports/custom-view-samples/filter-items-by-comparing-two-fields ...

No. The only other way to accomplish some of this would be to "subscribe" the second individual to the issue. This would get them copied if someone "comments" on the issue, but doesn't do anything if the issue is closed out (as an example). For this and other changes you think they would want to see...

I sometimes get this sort of error when my Filters are slightly off. As a troubleshooting step, you could start a new project report with no filters or groupings or any sort and just add that one column and sort by it. If this works, then you know something else is wrong with your current report.

I don't believe there's a way for an unconnected task to reference a request's form fields without some help, which you can provide either by linking the two (having the request resolved by the task's completion for example, or via a Fusion automation. 

I'm getting a "must specify an ID to edit" error, and none of the ID fields seem to be acceptable (tried category ID and parameter ID). Is this what you ran into as well?   I'd like to have found a way to link down to the CTGPEX ID itself similar to what you did above (cat ID + parameter ID + catego...

Can you just do  /attask/api/v19.0/task/search?projectID=XXXXX&milestoneID_Mod=notnull&fields=project:*

sorry I don't understand your goal. Are you being asked to pull in tasks where milestoneID is not null, or ALL tasks in the project?

Have you ruled out going through the ctgypa itself? It's the end of my day but I'm happy to look into ctgypa tomorrow if you haven't ruled it out -- just tell me what issues you're having with it so I don't have to replicate all your errors.

are you converting the request to a task? I'm having problems picturing how the information is going to get onto the task without this link.

no -- instead, we often recommend that people just set up a custom section that is a dashboard, and have anything you need to be on that page.