Possible solution to use the block.json way with ACF

register_block_type.php

<?php

/* DEFINE ACF BLOCKS */

if ( ! function_exists( 'my_acf_block_types' ) ) :

    function my_acf_block_types() {
		
		$color = '#2271b1';
		
		$block_types = array(
			
			/*
			'block_name' => array(
				'assets' => array(
					'editorScript' => '',
					'script' => '',
					'viewScript' => '',
					'editorStyle' => '',
					'style' => ','
				),				
				'icon' => '',
			),
			*/
			
			/* 
			* MY ACF BLOCK 
			*/
			
			'my-acf-block-name' => array(
				'assets' => array(
					'script' => 'my-acf-block-script.js',
					'style' => 'my-acf-block-style.css',
					'editorStyle' => 'my-acf-block-editor-style.css',
				),				
				'icon' => svg_icon( 'my-icon', $color ),
			),
			
		);
		
		return $block_types;
		
	}

endif;

/* REGISTER ACF BLOCKS + ASSETS */

if ( ! function_exists( 'register_my_acf_block_types' ) ) :

    function register_my_acf_block_types() {
		
		$block_types = my_acf_block_types();
		
		foreach( $block_types as $block_name => $meta ) {
			
			/*
			* Register ACF block via block.json
			*/
			
			register_block_type( 'path_to_block/' . $block_name . '/block.json' );			
			
			/*
			* Add ACF block assets
			*/
			
			$script = isset( $meta['assets']['script'] ) && $meta['assets']['script'] ? $meta['assets']['script'] : '';
			$style = isset( $meta['assets']['style'] ) && $meta['assets']['style'] ? $meta['assets']['style'] : '';
			$editorStyle = isset( $meta['assets']['editorStyle'] ) && $meta['assets']['editorStyle'] ? $meta['assets']['editorStyle'] : '';
			
			if( $script ) {
				wp_register_script( 
					generate_block_asset_handle( 'acf/' . $block_name, 'script' ), 'path_to_block/' . $block_name . '/' . $script, array('jquery'), false, true
				);
			}
			
			if( $style ) {
				wp_register_style( 
					generate_block_asset_handle( 'acf/' . $block_name, 'style' ), 'path_to_block/' . $block_name . '/' . $style
				);
			}
			
			if( $editorStyle ) {
				wp_register_style( 
					generate_block_asset_handle( 'acf/' . $block_name, 'editorStyle' ), 'path_to_block/' . $block_name . '/' . $editorStyle
				);
			}
			
		}
		
	}

endif;

add_action('init', 'register_my_acf_block_types');

/* CHANGE ACF BLOCKS META DATA */

if ( ! function_exists( 'my_acf_block_type_metadata' ) ) :

	function my_acf_block_type_metadata( $metadata ) {

		$acf_block_meta = my_acf_block_types();

		$block_name = isset( $metadata['name'] ) ? $metadata['name'] : '';

		foreach( $acf_block_meta as $acf_block_name => $meta ) {

			$icon = isset( $meta['icon'] ) && $meta['icon'] ? $meta['icon'] : '';
			$script = isset( $meta['assets']['script'] ) && $meta['assets']['script'] ? $meta['assets']['script'] : '';
			$style = isset( $meta['assets']['style'] ) && $meta['assets']['style'] ? $meta['assets']['style'] : '';
			$editorStyle = isset( $meta['assets']['editorStyle'] ) && $meta['assets']['editorStyle'] ? $meta['assets']['editorStyle'] : '';

			if( $block_name === 'acf/' . $acf_block_name ) {

				if( $icon ) {
					$metadata['icon'] = $meta['icon'];
				}
				
				if( $script ) {
					$metadata['script'] = generate_block_asset_handle( $block_name, 'script' );
				}
				
				if( $style ) {
					//$metadata['style'] = generate_block_asset_handle( $block_name, 'style' );
					$metadata['style'] = 'file:./' . $style ;
				}

				if( $editorStyle ) {
					$metadata['editorStyle'] = generate_block_asset_handle( $block_name, 'editorStyle' );
					//$metadata['editorStyle'] = 'file:./' . $editorStyle ;
				}

			}	

		}

		return $metadata;

	}

endif;

add_filter( 'block_type_metadata', 'my_acf_block_type_metadata' );