I made a lovely potiron velouté . The recipe called for a whole potiron and a couple of spuds.
Usually for veg soups I avoid adding spuds, but -looking at the soup - I think they are what have made the consistency veloutesque, because when you liquidise with a stick blender it pulverised the potato cells.
A potimarron is not the same as a potiron! Yes, same species but there is a huge range of pumpkins each with particular characteristics. So potimarron has a much thinner skin (hence no peel), is often a modest size, and has distinct nutty flavour. I think it could be called a chestnut squash in English. So there are different common names to distinguish them all.
And the only use for a citrouille is a halloween decoration. Large and tasteless to me.