Add logic to enable blocks for oik-plugins and blocks CPTs

[bobbingwide]

Some plugins create blocks in categories that they create for themselves.
They use code like this. See https://developer.wordpress.org/block-editor/developers/filters/block-filters/#managing-block-categories

As you can see, this is only good for posts.
How can we change the code so that the custom categories are registered regardless of the post type? Is this time for a super hack or just some hardcoded category registration?

function my_plugin_block_categories( $categories, $post ) {
    if ( $post->post_type !== 'post' ) {
        return $categories;
    }
    return array_merge(
        $categories,
        array(
            array(
                'slug' => 'my-category',
                'title' => __( 'My category', 'my-plugin' ),
                'icon'  => 'wordpress',
            ),
        )
    );
}
add_filter( 'block_categories', 'my_plugin_block_categories', 10, 2 );

[bobbingwide]

Other plugins only enqueue their scripts for selected post types. e.g. in slides/index.php the filter function for admin_enqueue_scripts begins

add_action( 'admin_enqueue_scripts', function() {
	if ( get_post_type() !== 'presentation' ) {
		return;
	}

Attempting to override this, by commenting out the return, led to an error while trying to edit any oik-plugins CPT.

TypeError: Cannot read property 'presentation-background-color' of undefined
    at render (https://blocks.wp.a2z/wp-content/plugins/slide/index.js?ver=1572947862:1114:31)
    at renderWithHooks (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:15246:18)
    at mountIndeterminateComponent (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:17480:13)
    at beginWork$1 (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:18624:16)
    at HTMLUnknownElement.callCallback (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:341:14)
    at Object.invokeGuardedCallbackDev (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:391:16)
    at invokeGuardedCallback (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:448:31)
    at beginWork$$1 (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:23355:7)
    at performUnitOfWork (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:22346:12)
    at workLoopSync (https://blocks.wp.a2z/wp-content/plugins/gutenberg/vendor/react-dom.8b3dda97.js:22323:22)

For other posts types the results were also rather interesting.
I automatically generated a block CPT for the Slide block.
When I edited it every block became a slide.

The Chrome console log is interesting reading, showing:

Block validation failed for slide/slide
messages for each block.