When you do an Auto Layout, XLights always fills up the last Universe of the controller so that it's an even 510, even if there are unused channels.
This causes a problem if you're trying to split a Matrix or Megatree across multiple controllers using shadow models.
e.g. I'm following Keith's video from here, but he has the same problem:
https://www.youtube.com/watch?v=VKSyxB14-SE
His MegaTree is set up to run from channel 1 to 9600. His left shadow tree is configured as 4800 channels on controller 1, and right shadow tree is configured as 4800 channels on controller 2.
However, the controller #1 last universe gets filled out to the nearest 510, so it isn't just 4800 channels, it gets 5100 channels (7:54 in the video) on each of the controllers.
So that means the first 5100 channels of the MegaTree maps to controller #1, (with the last 300 of those channels off in the phantom filled out universe that has no string mapping), and the remaining 4500 channels goes to controller 2 which means 300 channels are dark.
If you follow his instructions exactly, then at 8:28 instead of dropping effects on the shadow trees overall, you expand the two shadow trees in the sequencers and drop an effect on the individual strands then it becomes obvious. You'll notice there is a missing/skipped string between Tree Side 1 #16 and Tree Side 2 #1, and then Tree Side 2 # 16 never lights up.
Is there any way to make this actually work while remaining in Auto Size / Auto Layout mode?