I have been using supermetrics for some time now.
But I cannot use it for data from Mailchimp, it only returns 3 rows of data.
If I select all automation I always get an error.
If I use individual campaigns or automations, it is working but with limited data.
Mailchimp is an important channel for me to include in my reporting.
there are quite many limitations when it comes to using certain metrics and dimensions with different campaign/list/automations. You can read more about this from here: https://support.supermetrics.com/support/solutions/articles/19000081818-incompatible-fields-illegaldimensionmetriccombinationexception