Would love to be able to open a built-in dictionary/thesaurus in the inspector. I tend to keep dictionary.com open while I write, but it would be much easier if I didn’t have to click outside of Scrivener. Could just open the inspector, and have it right there on the right side of the screen.
You might want to search this Wish List forum for prior requests for this sort of thing and read the existing answers to this. By way of example, here is a pertinent thread: