It got me as I don't know the correct way to "break through" here.
Edit: weeks and many attempts later, I,ve got it and the solution seems so simple I should be smacking my forehead repeatedly.
It wasn't necessary to make it that big. If smaller, it would be less obvious. As is now, the distance to be covered with one back and forth consuming already >30 moves... That tells what to do. :D
Insights