Having figured out a way to get down the hill the right way up on Arosa and successfully making multiple trips down I've published the tutorial on YouTube. If you've been screaming at your screen with its upside down train wondering what happened well you need this .
You must have more passengers this time. Whereas you use exactly 31% of train brake, I went with 23% and I got all the way down, using more dynamic of course. It’s very enjoyable.
I have ts2.passenger.DensityScale=5 in my engine.ini which is quite a lot of people. I had it at 8 but that was causing performance problems on big routes and also meant I was leaving people behind at stations. They only seem to get in if there is a seat for them which is actually pretty cool. Paul