Block styles variations

To add a new block style :

<?php

function dsfr_register_block_styles(){

	register_block_style(
		'core/paragraph',
		array(
			'name' => 'highlight',
			'label' => 'Mise en avant',
		)
	);

}

add_action( 'init', 'dsfr_register_block_styles' );

The core styles are editable in the theme.json, but not the custom ones.

{
    "styles": {
        "blocks": {
	    "core/image": {
	        "variations": {
		    "rounded" : {
		        "border": {
			    "radius": ".5rem"
		        }
		    }
		}
	}
}

https://fullsiteediting.com/lessons/modifying-block-style-variations-via-theme-json/