Do you happen to know anything about using pumpkin puree? Like when I steep it is that enough to cook it or should I heat it up prior to steep it since it's not really cooked?
If you aren't mashing, I'd skip the pumpkin. Most of the "pumpkin" flavor in a pumpkin beer is from the spices anyway, and you'll avoid the issues with having excess proteins and starches in the finished beer.
I've read some recipes that call for spreading the puree out in a thin layer and baking it in an attempt to caramelize the starches, but I haven't tried it myself. I'd imagine that would force out a lot of the water and make a mess though.