Text formats not properly processed in Splashify entity

Use case: embed a webform entity in Splashify

I have entity embed fully setup and working in all content types. I can embed an entity anywhere and it works - except splashify. Screenshots show some basics, but essentially the entity embed token remains unprocessed in the outputted markup.

Note that in the WYSIWYG editor, it does correctly preview the rendered entity in the editor.

I tested this in both plain text (which didn't work - as expected) and template mode. The code that outputs template mode uses $entity->getContent(), though.

I inserted the following before the splash type switch and this does work.

return $entity->get('field_content')->view();

So I think the $content variable needs to be constructed differently - in my case I don't need all entity fields, but it might use the ->view() methods on each field and combine those. There should also be a mode that supports HTML output without using a template.