Rated 3 out of 5 stars
TMT is not suitable for working with named tab rows like with topically grouped tabs. This is because it treats the FF tab bar differently then the TMT tab rows. In particular, TMT doesn't allow to switch content of the tab bar with selected tab row easily.
Instead, TMT works with tab rows rather like with bookmark folders - tabs are hibernated in tab rows, and to activate them, you have to move them to the tab bar. For topically grouped tabs, TabGroups Manager is much more suitable.