Adding content sources for dynamic CSS generation

I know: GP has no form fields. But I noticed something and I would like to address it here: Form fields are partially shot up. Especially if you use JetFormBuilder. I have not tested other form builders.

My goal is to put the fields in different columns. What i get is this:

The fields do not spread 100% over the entire width. When I use the default block of wordpress, it looks fine. Nothing gets shot up. See the two fields below the form:

The second thing I noticed: I use the headline block to make the note a little nicer. In the editor it shows up, but in the frontend it still looks like “standard”.

I have the feeling that the styles do not “grab”. So i have to got this way: Adding content sources for dynamic CSS generation (can’t insert the link, but there is a GB documentation)

My question now is: how?

Do i have to change only this element:

if ( ! $block_element || 'your_post_type' !== $block_element->post_type ) {
        return $content;

to this:

if ( ! $block_element || 'jet-form-builder' !== $block_element->post_type ) {
        return $content;


What would I need to do to make all forms adopt the GB Styles? As independent of the ids…

$post_id = 123; // A post ID to check the content of. Can be dynamically set.