@corvinus26 if you have certificates to boost your CV then much better. If that is your way to sell your qualifications to potential employers then do it. Never think na konti lang ang ang competition mo so you need every advantage to get noticed. Pero so far wala naman nag ask ng certificates ko during interviews.
Ako since im in architecture industry, i focused more on my portfolio to get noticed. I built websites, online portfolios and check the stats kung ilang potential employers nagvivisit.
as for your QS/estimator position, im sure most employers would prefer with OZ experience lalo na yung may familiarity sa labor and material costs. My current employer hired me for my experience in hospitality projects yet pagdating dito ibang iba yung hospitality requirements nila. Yung softwares pa na ginagamit nila is different from what im using. But luckily they are more than willing to guide me along the way. In short, Its really up to the employers if they are willing to take a chance on you.