Your mechanical engineering background will clearly not be of any use, because it is probably in a completely unrelated field.
what would happen if say you stick a petrol Dsg file on the mechatronic of a diesel dq250 ?
Asking this question shows complete lack of understanding of how the gearbox works.
The questions you are asking are not technical. They are something that you can find in <5 minutes of Google usage.
If you can't accomplish that, you are never going to get this gearbox to work, end of story.
You're not entitled to any help. But you are receiving a recommendation from someone who did this for a living for over ten years.
I've done the exact thing you're trying to do. It took me over 20 hours the first time, I knew
exactly what I was doing.
Re-calibrating all the shiftmaps from complete scratch and sorting out the shift gradients just takes a shitton of time and driving, and that's when you have all the tools and data + full knowledge of how it works.
You're gonna take 200+ hours. I don't care if you got the box for free, it's cheaper and much better for the end result to buy a petrol box.
Playing victim here and whining is not going to get you anywhere whatsoever, nor is anyone going to give you a handout.