ACF gallery field. Merge serialized arrays php

gistfile1.txt

	<div id="main-content" class="is_fullwidth home-template">
		<div class="container">
			<div class="row">
				<div class="col-xs-12">

					<form method="post">
						<p>
							<textarea name="galleries" style="width: 500px; height:200px;"><?php echo ( isset( $_POST['galleries'] ) && ! empty( $_POST['galleries'] ) ) ? stripslashes( $_POST['galleries'] ) : ''; ?></textarea>
						</p>
						<p>
							<button type="submit">Go Go Go!</button>
						</p>
					</form>
				</div>


			</div>
		</div>
	</div>


<?php

if ( isset( $_POST['galleries'] ) && ! empty( $_POST['galleries'] ) ) {
	$galleries = trim( stripslashes( $_POST['galleries'] ) );

	$galleries_split = $skuList = explode( PHP_EOL, $galleries );

	$galleries_merged = array();

	foreach ( $galleries_split as $gallery ) {
		$gallery = trim($gallery);

		$array = maybe_unserialize( $gallery );

		$galleries_merged = array_merge( $galleries_merged, $array );
	}

	debug($galleries_merged);

	debug( maybe_serialize( $galleries_merged ) );
}
?>