You shouldn't have so many LED fixtures. LED scanner is ok for small installations or to detect LED bars. But if you have 30000 pixels, don't detect them as independent pixels. I suppose your LEDs are not disposed randomly.
We have much bigger projects running (more than 400 DMX universes) but we use a fixture per LED bar (from 20 to 100 pixels). So we have much less fixtures than pixels. The performance issue happens when manipulating hundreds fixtures, it's not related to number of pixels. So I suppose you can solve your issue by discovering DMX lines instead of pixels.