All mentioned above seems to work as expected in Browse mode, if user editing a field and using the ruler, creates and uses tabs in this way. Even the leaders work. So I did same way in Layout mode. The Tab requester has a set button, which applies your changes. and this did work.
But I haven't been successful doing this in edit layout mode using the inspector panel and tab section.
If you need to setup tab stops, its best to use the ruler and the tab requester, rather than the inspector