How do I debug SAP ATC (ABAP Test cockpit) test runs?

I am running ATC (ABAP test cockpit) tests from SE80 ABAP workbench.

It is not the first time that I do not understand an ATC test result. (SAP standard check) (I am a developer, without experience as ATC administrator)

What are good breakpoints to see how SAP tests ABAP code and/or emits test result to the ATC result list?

I find it hard to start an ATC test in the debugger from SE80, since the right mouse click to start ATC already invokes the debugger.

I have no rights for transaction ATC.