filter-row-settings.php

<?php

function filter_bb_layout_data( $nodes ) {

	// Loop through the nodes.
	foreach ( $nodes as $node_id => $node ) {

		// Update row settings.
		if ( 'row' === $node->type ) {

			// Check for the old setting to update.
			if ( isset( $node->settings->old_setting ) ) {

				// Change an old setting to a new setting.
				$node->settings->new_setting = $node->settings->old_setting;

				// Make sure to unset the old setting so this doesn't run again.
				unset( $node->settings->old_setting );
			}

			// Save the update settings.
			$nodes[ $node_id ]->settings = $node->settings;
		}
	}

	// Don't forget to return the settings when you're done!
	return $nodes;
}

add_filter( 'fl_builder_get_layout_metadata', 'filter_bb_layout_data' );