Firstly, it doesn't make much sense that the Table of
Contents menu item is under "Insert"; when you want to
update it, you have to go to Insert -> Table of
Contents -> Update. Perhaps it should be under "Tools".
Secondly, having it updatable via a right-click (as in
MS Word) would be very nice.
Thirdly, it should be able to remember what levels of
headings are included in the ToC so that the user
doesn't have to re-enter them each time it's updated.
For example, if I only want to list h4 elements, I have
to click every single nest level to set h4 as the first
level and the rest as nothing.
Thanks for your great work and good luck!