I hope you’re not seriously telling me that they would be significantly more satiating if they were made with butter instead of vegetable oil

You’d be in for a surprise…

There is this thing called clarified butter (Ghee) and you can actually cook in it (not affordably though, as any good quality one would be in Olive oil like category).
I tend to try it out a few times (because it is still way cheaper than eating out, where they would still use palmoline despite their markup) when I am free and although heat control can be tricky depending upon the Ghee source and target recipe, it can make a great difference.