We've installed this extension without any issues and the connection to the mautic was very simple. All our customer data now automatically goes to mautic including custom customer attributes that we have, that is really great.
Magento 2 Mautic plugin uses Mautic API to send data from Magento2 to Mautic, so your Mautic instance can be hosted on the separate server (if needed). It sends orders data (including guest orders), subscribers data, customer reviews data and customers data. In this way, you can achieve maximum integration with Mautic.
Asynchronous Data Export
All API calls (requests) to Mautic extension run asynchronously by Magento 2 cron job. This doesn't slow down your online store and doesn't make customers wait extra 0.5-2 seconds while a request is returned from the Mautic instance. When some data is added or changed extension knows this and schedules the export.
This Magento 2 extension is easy to configure and connect with the Mautic. It has fields mapper which helps to relate each customer attributes (even a custom customer attributes) to Mautic contact field.
Example of Magento 2 Customer and Mautic Contact