We have found with normal rosin extractions from flower, which are pressed at 200 degrees with a 30 second "warm up" and 60 seconds of press (Could go a bit longer though I think), we run the nail at 625 - 630 degrees. The terps are insane at this low heat. With the hash rosin, the waxy stuff, doesn't melt the way it should I noticed last night. So the rig got turned up to 700 and it melted a lot better and the flavor was still there. Tasted just like the flower does as well, very blueberry.
We are still in the 'experimental' stages of all of this so still trying to figure it out. I've started to go through shigg's rosin thread again lately trying to see if we can get it dialed into perfection.