Firefox has session restore, which also works when the browser is closed abruptly. Is it now working for you?
Also it lacks the granularity of session buddy, which has a list of every tab and window configuration I've ever had.
I do use nightly though. I have like 100 tabs open, and I would know if I was missing any of them. I need them all. ALL OF THEM.
These bugs suck for everyone and I'm sure Mozilla developers would appreciate any help they can get to track it down.
These will behave differently: (1) "Quitting" Firefox will multiple windows open. (2) Using your WM to close both Firefox windows. The latter will cause only the last-closed window to be restored, but you can pop the others off the stack too with Ctrl+Shift+N.
In fact, it's one of the larger reasons (tabs constantly crashing is the largest one atm) I leave Firefox for side jobs instead of being relied upon as my main browser.
For more features, I'd recommend looking at either the Container feature, that might be able to help, or otherwise third-party extensions - maybe another commenter has a recommendation, since there's a giant number of tab management extensions, and it's hard to tell which ones do what perfectly.
If you search around a bit in the sidebar menu you’ll find a list of all the open and previously open tabs on any of your PC’s. Including ability to restore all of them at once.
Not sure if it’s quite the same thing.