If it's fixed, don't ride it on the platforms, keep clipped in.
+1
Fixed on flat pedals is hellish. Get the speedplays on tonight.
Oh, I don't know about that. I prefer to ride clipped in but I've had no problems controlling my fixed bike using the platform side of its A530 pedals. One thing you learn is to angle your foot heel-down when slowing yourself down with your legs. I wouldn't ride as fast or as far without foot retention as I do when clipped in, and I would be very careful going over speed bumps and the like, but I wouldn't call it hellish. Quite fun, in fact.
That said, I think the flat side of the A530s gives greater control than those M324s; you can feel the whole surface under your sole, rather than having those jagged edges pressed into it. I have M324s on another bike and still have a few scars on my shins from those edges.