Honestly the bike doesn't fit you if you want to raise it that much. 10mm = 1cm = a lot of movement vertically. Implies the bike doesn't fit.

As others have mentioned...you can't just add spacers to the "max the manufacturer recommends" if the steerer tube has already been cut ....which it probably already has.

You have to work with what is there. The clamp on the stem has to be almost fully engaged with steerer tube. You only get a mm or 2 to mess with to allow proper preloading of the headset bearings (making sure there is a 1-2mm gap between the top of the stem and the top of the steerer tube so that you can tighten the top cap without bottoming out against the steerer tube)...

In other words if you add your 5mm spacers to a steerer tube that has already been cut then when you preload the headset and tighten the clamp you stand a good chance of causing the stem or the steerer to fail under load - you reduce the clamping force of the stem on the steerer due to lower clamping area.

= looks god in the stand, but gets rider killed on the road.

Thank you for asking though because although I believe in Darwin's general thoughts I think that asking for help on the internet constitutes a beneficial mutation that allows the rider to survive.