I remember now that on the Mautic Con there was a speaker who presented the integration of Mautic with Matomo and Drupal for content management. As far as I remember they were writing the code for integrating the three, and they offer some specialized solutions in this field. So their system can do profiling and serve individual content for every visitor and things like that.
In my case I decided to make GDPR conformity a preference, and since you need a consent to do profiling, I decided not to do any of that. I even set up Matomo to read my log files and do the statistics totally without cookies, so I do not need to ask my visitors for any cookie consent. The next step will be for disabling the website tracking in Mautic, so I will be totally cookie free.
Now I think some goal tracking in Matomo could be nice, like how many have signed up for a certain newsletter, so I know the conversion rate of my opt in pages. Probably the easiest way to do that is doing some kind of API calls. Theoretically it is possible to fire some webhook directly from a Mautic campaign, it may be possible to trigger a tracking even in Matomo this way, but this is rather complicated. The elegant way would be a Mautic plugin that is able to send tracking events to Matomo. Having that, you can track anything you want in Matomo what is happening in Mautic, and in a simple and user friendly way. I was never writing a Mautic plugin, but maybe one day I could have a look into that. Surely would be an interesting thing.