I'm using 250 pixels on my roof with LOR S3 3.8.0 advanced. Because of the new E1.31 support and the way the Etherdongle supports Multicast, I did not need to use xLights to run my show.
Also, because it seems easier on my brain, I haven't been running over an Universe boundaries.
For example, the 250 pixels I have need 750 channels, exceeding the size of a single universe. I'm using one Active Hub and 4 SSCs. So, on the first 2 SSCs, they are Universe 6 (in LOR), starting at channel 1 up to 375. The other 2 SSCs are Universe 7 (in LOR) channel 1 to 375. LOR let me add a "Device" on Universe 6 with 384 channels. I just deleted the extras.
That same Active Hub is also pulling out DMX data on Universe 3. My 2011 sequences used Universe 3, so I didn't have to change much.