It would be n to nice have spell check functioning not only while editing text objects, but on everything shown in the layers panel (including page names), as well as on Sections, Frames, Groups etc. Pretty much any where there is user input available and the misspelling indicator would show even if the user is not in editing mode.
Canvas:
Layers (and pages) Panel:
Properties Panel:
Looks like there is already some spell checking going on in the properties panel- yay!