If this Giro had more kms of ITT I'd actually back Kämna as Bora's best gc option in this race.
He likes bad weather and loves multi-mountain stages.
I'm not sure if he's good enough on the steep stuff to do this. Also his TT was quite shaky until this year. I think it's clear that he has all the tools to be in the TOP 5 in a GT if he wants to focus on it. But with his break last year and the motivation stuff maybe it's best to ride this attacking style and set goals for individual days.
Also with this form he could come in quite handy as a helper for Bora. He has now his stage victory and I think he could go for the mountain jersey as well, but Bora has three leaders in the Top 21 right now with Kelderman only 13 seconds behind Yates. I think that will be his focus in the last week. They must feel quite confident with Buchmann als trying to set the pace there for a small period.
Let's see how it will look on Blockhaus, with no real attacks today there will be some people in GC G1 that bluffed themeselves through the last hard parts of the mountain.