I've been dabbling in raspberry/hibiscus wheat beers of late (just kegged another 10 gallons today) using homemade puree - without seeding first. So, pretty much rules out dumping the puree directly in a keg, so I do in fact rack into a dreaded "secondary" vessel with the puree within with a half-cup of CS and let that simmer for four days before kegging. When I look at the mass of seeds and berry skins left behind after kegging I'm convinced I'd have to buy spendy processed puree to go straight to the keg...
Cheers!