Unfortunately, right the first one I tried was rejected. I guess more may follow, so I could imagine this thread as a collection of reports... if the development agrees.
- Save Session "could not be installed because it is not compatible with Basilisk version number" (but it still works in Pale Moon 27.6.1); this add-on provides a feature to save a session while closing the browser, which is automatically restored next time the browser is started; there are many feature-rich session managers out there, just no other seems to provide this specific feature, which is especially useful when e.g. a Windows Update urges to reboot in the middle of your work...