Brad,
I am not an uboot expert, but I would say logically that's what you can assume. If you have any detailed question regarding uboot you would need to ask in the Sitara forum.
Basically how the flash process works is that, the binaries to be loaded are packed together into a big image file hosted on the tftp, and this debrick.scr, which is basically a uboot script, is loaded over and instruct the device on how to flash itself.
Note that debrick.scr is compiled through an utility in the Sitara SDK, not a regular text file.
Questions involves image packing should be directed to the Sitara BU, but in essence you don't have to follow that packaging since you are modifying the debrick.scr.
Victor
Victor