I am bumping thic topic.
What's needed to write such converter? I would donate, others would do the same I guess.
1. Reverse SGO format enough to parse it.
2. Reverse the bootloader on every single ECU type you want to convert.
EDC15/ME7/ZF6HP/MED9/ME17 are BCB/XOR. Some have fixed key, others like EDC15 have a different key for every ECU file and version.
Other ECU's such as EDC16 and SIMOS have a completely different algorithm that can be only obtained by reversing the the bootloader.
I would happily write a converter if somebody can post the specs to the sgo file.
With all due respect, I don't think you are going to break the crypto on EDC16 for example. You need to pull the bootloader apart one by one, it is a very time consuming process. The SGO is easy to reverse even without any specs.