Meta Box

Have a workaround for this, but it's not ideal as to implement you'll need edit the plugin.

I install the plugin into the theme so it's not an issue, but if it's via the WP Plugins system the edits will get overridden.

File: mb-blocks/src/Block.php

Find $attributes = wp_unslash( $attributes ); on line 81 and add the following after that.

`
if ( empty($attributes['data']) && ! empty($this->meta_box['defaults']) ) {
$attributes['data'] = $this->meta_box['defaults'];
}

`

Then on the block config array, you can add a defaults array key containing any default values you want the block to render with. In doing this you bypass the UX issue described.

Quick/dirty work around for this would be to just use the mb_blocks_preview JS callback.

e.g.

    function init__container(e)
    {
        console.log('init container');
        console.log($(e.target));

        if ( $(e.target).find('> .components-placeholder').length > 0 ) {
            setTimeout(() => { 
                $('.mb-block-edit select, .mb-block-edit input').trigger('change')
            }, 1000);
        }
    }

    $(document).on('mb_blocks_preview/odin-container', init__container);