I had worked a bit on a program before LDON. With augmentations already in the item data format, I didn't believe it was likely they would alter the data structure of the items when LDON released. I was wrong.
The good news is the new data format is very similar to the spell format used for the last few years. It is much easier to parse items with this format. I suspect they moved to this format to ease their troubles with debugging items when making sweeping changes. I doubt they will ever go back to the C structure format again.