avoiding slab to matrix for alpha blending

Hi all - I've got a patcher that's nearly done, but I'm not happy with the performance. I read about the vade optimizations and watched the cycling74 tutorial on optimization. I've tried various combinations of things to get my framerate up - which you can see in this patch, such as qlim on the preview monitor, unique 1 on the movies, disabling onscreen on the preview window, etc.

One thing I have a feeling is that, while I'm rendering a syphon live camera feed and a movie together on a slab, I later use a matrix to alpha blend that with another video. I feel like there's a way to accomplish this while maintaining the use of slabs, but I haven't figured it out.

At any rate, if anyone is willing to have a peak at the patch and suggest some optimizations, or even point me in the right direction, I'd be incredibly grateful. Thanks!