Figuring out who is using custom macros and/or governing the macroverse is not an easy task currently.
I have started shipping Alteryx logs to Splunk to see what could be learned. One thing that I would love to be able to do is understand which workflows are using a particular macro, or any custom macros for that matter. As it stands right now, I do not believe there is a simple way to do this by parsing the log entries. If, instead of just saying 'Tool Id 420', it said 'Tool Id 420 [Macro Name]' that would be very helpful. And it would be even *better* if the logging could flag out of the box macros vs custom macros. You could have a system level setting to include/exclude macro names.