Change a license activation limit prgramatically.

/**

 * Conditionally alter the activation limit for the a license key.

 * 

 * Example: Licenses created prior to 2020 are set to unlimited.

 * 

 * @param int $limit         The current activation limit.

 * @param int $download_id   The download ID for the license.

 * @param int $license_id    The ID of the license.

 * @param int|null $price_id The variation price ID for the license (numeric for variable priced products, null it not)

 * 

 * @return int

 */

function eddwp_change_license_limit( $limit, $download_id, $license_id, $price_id ) {

	// Change the limit if a license was purchase prior to 2020 using the date_created property.

	$license = edd_software_licensing()->licenses_db->get( $license_id );

	if ( empty( $license ) ) {

		return $limit;

	}

	if ( ! empty( $license->date_created ) && strtotime( $license->date_created ) < strtotime( '2020-01-01' ) ) {

		$limit = 0;

	}

	return $limit;

}

add_filter( 'edd_get_license_limit', 'eddwp_change_license_limit', 10, 4 );