Unbelievable! Got it straight on my very first try! May I give it 6 stars? :D
To explain though: there is something I spotted while studying the initial configuration. I decided it can't harm to start with that, and the rest followed logically. So to check the board at start can give the key. :)
Out of the two methods I use, one brings me too far and the other 2 off but is optimized... There must be 3rd way to go...
** day after **
That was a mix of the 2 methods LOL
The usual for me: I had a 2 off and struggled to solve it. Eventually, one route worked. Why this path and not one of the earlier tries... Can't "see" it.