Image block defaults

Hello,

there was this discussion https://wordpress.org/support/topic/default-margins-for-containers/#post-13025697 a while ago.

I would like to have defaults in posts and pages for the image block to be:

centered
large size
padding 48px

Following the logic from the discussion I listed above and some more searching i have tried this.

function apuri_generateblocks_spacing( $defaults ) {
	$defaults['image']['alignment']      = 'center';
	$defaults['image']['sizeSlug']       = 'large';
	$defaults['image']['paddingTop']     = '48px';
	$defaults['image']['paddingRight']   = '48px';
	$defaults['image']['paddingBottom']  = '48px';
	$defaults['image']['paddingLeft']    = '48px';
	return $defaults;
}
add_filter( 'generateblocks_defaults', 'apuri_generateblocks_spacing' );

I have also tried setting the global styles like this.

add_filter( 'generateblocks_default_block_styles', function( $styles ) {
    $styles['image']['alignment']      = 'center';
		$styles['image']['sizeSlug']       = 'large';
		$styles['image']['paddingTop']     = '48px';
		$styles['image']['paddingRight']   = '48px';
		$styles['image']['paddingBottom']  = '48px';
		$styles['image']['paddingLeft']    = '48px';
    return $styles;
} );

No luck. What am I doing wrong?
Best,
Elvis