I read the 1-star problems of losing tabs so I tested this install with 40+ tabs.

40 +tabs open. They reduced to one tab and Task Manager showed savings. Hit restore all and they all came up fine.

closed FF and did it all again. This time saved the single OneTab bookmark and closed FF without restoring the 40+ tabs. Restarted FF and opened the saved OneTab bookmark. All previous tabs were listed. They opened both individually and as a full group and worked fine, including this page.

Seems to work fine. I'll keep it.