It looks like you solved it, but posting the instructions here for anyone else with the same question:
To use with Pixelblaze, change the LED type to “Pixelblaze Output Expander” - then click on “Add Board” for each connected expander board. The interface will let you set up each channel’s start index and pixel count. A count of zero effectively disables that channel.
For more than one board, some of the cuttable jumpers need to be nicked with a utility knife (or anything that can put a good nick in the board). Each board has 3 jumpers that set an address between 0-7, which is then matched up in the config panel dropdown near “Board @ Address”
Here’s the chart showing how to set various addresses and which jumper to cut:
