Wordpress - Is it possible to access Gutenbergs reusable blocks in CPT block templates?

I actually found a solution myself by following the way a reusable block is registered in this stackexchange thread:

Reusable blocks are all stored in/as core/block and this block has the attribute ref which carries the post id of that block.

So, you can use

array( 'core/block', array(
 'ref' => [your block ID],
) ),

and the ID of every registered block is visible via the URL of that block at [your-wordpress]/wp-admin/edit.php?post_type=wp_block