I've just made these, with dried cherries as the fruit (well chopped).
I found that I couldn't even get half the popcorn into the bowl to begin with, and then the 'toffee' started to harden long before I could get all the popcorn incorporated in a mixing bowl. I think I ended up with 1/5th to 1/4 of the popcorn remaining.
Spreading it in the tin was hard, so sticky ... ended up oiling my hands and just manhandling it.
Smells delish. It's in the fridge right now to cool. Hopefully it won't go soft too quicky, but I think that for it to *not* go soft, the popcorn really needs to be completely covered in the toffee mix, which hasn't happened.
We'll see.