Simple title, simple question, but actually I'm really wondering if they all work together? On Drupal, it's a full Yes but what about WP?
I can send simple HTML but any template using css would fail.
I've already post this and then I read this message from MattWire on Mattermost talking about an extension to make Smarty and Mosaico working together even though I'm not using Smarty logic in my templates. And also read this post saying you can't use Smarty and Mosaico together, but maybe this is off topic.
Entities is set to boolean, I have last version of Mosaico, CiviCRM, Flexmailer, and smarty defined to 1 in settings.php
I've also tried my template on the demo without any issue.