I do a Smashing Pumpkin every year around Halloween. I skin and chop 4 pie pumpkins and bake them in the oven with brown sugar and cinnamon on top. I add two pumpkins to the mash and 2 to the last 20 mins of the boil. The first time I wasn't sure if it would cause mash issues so I put them in a muslin bags. Found out that when I chop them into pieces and bake them, it didn't cause any issues so I don't even bother with the bag anymore. It might be different if you were using puree or pie filling. I'll add a picture once my phone done updating for reference.
Here’s before baking: