I own a 3m blade 2 and am 100% sure you can powerslide with it, you can pretty much do any trick you want reguardless of kite size, you just need more wind and it'll just be a bit more fiddly getting the technique right cause it'll be much more twitchy compared to a bigger kite. 3m's are very able kites in the right conditions, in the past ive pulled sum nice grabs, and foot outs with 1 altho i'd not advise it, pulled a foot out, not redirected and looped the kite firing me into a fence.
i'd try taking your 13m out in sum lightish winds where you can get goin on the board and needing to edge up wind just a little to stay fully in control. then to powerslide force your trailing foot away from you till its just slightly less than square on to the kite then slowly redirect the kite back accross the window fairly high up and just lean back to absorb the power a bit an you should start to skid nicely, then just reline up you board before you scooting off downwind in the other direction.
hope that helps
Graham