I'm gonna advertise a climb that I recently did on my roadbike:
The Penser Joch/Passo di Pennes has only been used twice by the Giro, 1961 and 1995, and both times they used the easier side of the climb.
In 1961 it was a brutal Trento Bormio Stage with Penser Joch, Jaufenpass and the Stelvio before a downhill finish in Bormio.
In 1995 they also used it as the 3rd to last climb on a stage that ended with a Schnalstal/Val Senales MTF.
Now the northern side of the climb is a different beast,
15.8km at 8% with the final 13.5km at 9.1%.
This side of the climb only features 4 hairpins, but it still has some stunning sections.
Now, how can you use this climb? A MTF would be the most boring option, I'd go with a downhill finish in Sarenthein or even better, an easier uphill finish at the Reinswald Ski station.
You can always have the harder side of the Jaufenpass/Passo di Monte Giovo right before it (there's almost no flat between the 2, a natural combination) and if you wanna make it even harder you can have a short stage with the Timmelsjoch/Rombo from Sölden.
Here is a potential short Reinswald stage from Sölden that I've come up with:
https://www.cronoescalada.com/index.php/tracks/viewTour/622939
Of course you could also make the stage longer and put something else before the Jaufenpass, have a hard MTF like Bondone, Alpe di Pampeago or Meran 2000 (just to name a few) the day before and we'll see really big gaps on this one.