I don't remember the specifics of how to do it, but you can disable the Firefox upgrade welcome tab... My Firefox install hasn't bothered me by opening any unw

I don't remember the specifics of how to do it, but you can disable the Firefox upgrade welcome tab... My Firefox install hasn't bothered me by opening any unwanted tabs in a couple years, at least? But it still updates on a system restart or when I tell it to -- it just reloads all the previously opened tabs without any UX burden.