Out of interest what extra do you think you’ll be able to do with an added 13mm of travel that you can’t do now? It may be a better idea to sell your Giant frame and replace it with something designed with more travel if you feel thats what you need.
Well, you’d have to (effectively) move the back wheel downwards, lifting the bottom bracket (shortening the bike slightly?) and steeping the head angle. So, yes. And it could well ruin the handling too.