MB Race is the only event like this I’ve done – but I really enjoyed it. Didn’t seem that technical apart from some fast descents and some steep climbs (up ski slopes!) but varied and fun with a good atmosphere. Not sure if it’s the same format now, but when I did it you could choose to continue on a longer distance or stop if you’ve had enough.. or if you’d blown up your rear shock like my friend did 😮
There are a few other events that are slightly outside your criteria – not in the Alps or multi-day, like the Transmaurienne, Quebrantahuesos MTB, Lozerienne, Forestiere, or even the Roc d’Azur/Roc des Alpes.
Oh, or the Velo Vert VTT festival at Villard de Lans