It does what it should and that very good for me since 2 months.
But when restarting FF and opening last session via Tab Session Manager the tab order ist lost. I did tests now by saving and reopen of a (one) window:
Reopening works fine when active tab is the most right one.
Atherwise only the tabs left to the active one are correct after reopening. The tabs to the right of the active one are reopened in wrong order.
What I found saving is not the problem it's the reopening !
Whould be nice to hear if you found that as i do and more nice if you would correct this issue.
kr johann