Here is Foppe from the Netherlands,

I am interested in Lupo 3L 1.2TDI tuning tuning stuff.
My main goal is to be able to activate cruise control because these ECU's don't have it activated that's why the tuning comes in.

Still a newbie and will take my time, but I will get there. ;)

I made some progress. First I know how to change the 2 ECU versions using VAG EDC15 suite.
I discovered the checksum is calculated automatically when checking the checksum and saving the file.

So now I can flash the ECU, as long as it is powered higher than 12,5V.

This weekend I will go try my first ECU read, check it with files I already downloaded and modify this file.
If all goes well, I will do my first write and do NOT touch any cables ;)