The keyword field is a feature that I discovered recently and have used extensively at work.
I noticed it does not show up when creating bookmarks using the Star button, but it does when right-clicking the tab and selecting "Bookmark tab" option, and I think this is a design failure. That feature is very useful, and, while the "add bookmark" dialog needs to be improved and cleaned up, I think it is necessary to show this feature in both when saving a new bookmark.
Please fix this problem.