$flexformTyposcript = $this->pi_getFFvalue($piFlexForm, 'myTS','s_TS_View'); 
if($flexformTyposcript) {
	require_once(PATH_t3lib.'class.t3lib_tsparser.php'); 
	$tsparser = t3lib_div::makeInstance('t3lib_tsparser'); 
	// Copy conf into existing setup 
	$tsparser->setup = $this->conf; 
	// Parse the new Typoscript 
	$tsparser->parse($flexformTyposcript); 
	// Copy the resulting setup back into conf 
	$this->conf = $tsparser->setup; 
}

		$flexformTyposcript = $this->pi_getFFvalue($piFlexForm, 'myTS','s_TS_View'); 
		if($flexformTyposcript) {
			require_once(PATH_t3lib.'class.t3lib_tsparser.php'); 
			$tsparser = t3lib_div::makeInstance('t3lib_tsparser'); 
			// Copy conf into existing setup 
			$tsparser->setup = $this->conf; 
			// Parse the new Typoscript 
			$tsparser->parse($flexformTyposcript); 
			// Copy the resulting setup back into conf 
			$this->conf = $tsparser->setup; 
		}

This can be used if you have a Flexform field where a backend user enters Typoscript that only pertains to that single instance of the plugin, not all instances on the page.

Merge External Typoscript with Default Typoscript

PHP