Thanks very much for your reply!
I got it to work best with the second option as the windows blocked each other. If anyone else using mac needs the info, I ran the following in shell:
export QTWEBENGINE_REMOTE_DEBUGGING=8080;
open /Applications/Anki.app;
open -a "Google Chrome" "http://localhost:8080/";
Then, once the Anki window you want to inspect is open, you need to refresh the dev tools page and click on the box with the right name. Full details of startup commands here.