Not sure of grav plugin I am new to mautic myself. Been using it for a week. Still in testing before I start using it as part of production website.
What I understood so far about Mautic is that... documentation is a little too technical for a non-IT guy to get around completely as majority of us never had the experience to play with server side of websites. Even with all the controls in your hand... it isn't easy.
This makes the problem two fold when inexperienced user ends up with a bug! So bug+inexperience = one crying community :D And I haven't even mentioned hosting services not being cooperative to run mautic the right way...
Mautic either needs more hands or more time to get mature... just like all other open source projects. This community however is dry of active developers or atleast those guys who can understand the problem users reporting here. Like I have no idea what to do if error pops up in logs unless its too obvious.
For me atleast its been 7 days and just when I say that yes now I'm ready! I hit a road block... like just last night... I had the system running... everything working smoothly atleast to the point I knew... and on update I have lost access to my contacts list... seems some kind of a bug... so I will have to wait for developers to come up with the solution may be...
If one can wait... and is not bothered by workarounds... and living with the issues it has... especially if you have no money to spend for other automation services... otherwise... disappointment awaits :)