I also used two of the big Libby cans for mine. I put my spices in at flameout. I used 0.15oz of cinnamon and it think it was a tad too much. But I had doubled what i planned to use because on brew day I discovered we were out of allspice.
I didn't roast my pumpkin. And I put mine in with the mash.
I think as long as you keep away from strongly flavored hops, you'll be fine. You want them to complement the spices, not clash with them.
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