I’ve done it 6 times now! Once solo and 5 times guiding groups!
Always Nth to Sth. The wind is occasionally against you but the trails flow better.
Not sure of best diy transfers, maybe the train might work.
2 days is a fairly solid challenge of around 100km/day. 3 days is a good comfortable trip for reasonably fit riders.
I enjoy the route, in an old-fashioned mtb-touring sort of way. Remote areas, great views and hardly a soul along most the route. A few fun singletrack sections as well.