An over approach to display the debug console in preview mode based on Google Tag Manager experience
After enable the preview mode, you have to go the the target site and add arguments to the URL:
Once preview mode enable, go the the target site with the same browser and the debug console appears alone.
To hide the console, disable the preview mode.
The preview mode manage a cookie into the browser to determine if the debug console have to be displayed or not in addition to the Matomo Tag Manager configuration.
That's it 🙂
Don't hesitate if you need some additional information.
Cheers @Laul0 closing this as a duplicate of https://github.com/matomo-org/tag-manager/issues/217 As mentioned there we are setting a cookie already, but this only works when both Matomo and the site itself runs on the same domain so far.