Hello,
my personal opinion is that your for offset should be chosen independently from your head tube angle. Of course getting into a hang five will be very easy with that combination and it would feel more "normal" if you would use a minimal offset fork, but: Think about the same trick with reverse bar position! Then it is even more special! So if you compensate it for one way, it is even more special for the other way. I would say if you have a 76.5 HT, you will have a steep HT, whatever other parts you chose
Many people like 74 ° but 75 ° is pretty much standard today. But in the past many riders used these Quamen frames, so I am sure you can get used to it. Maybe it is better for certain tricks. Give it a try!