Is there a setting or code to increase the default Ctrl_Tab stack before "show all 386 tabs", (which do NOT show in order visited)? Only 5 tabs are available. (Note- if you close the 5 tabs listed in the FF switch tabs dialog, it shows the 5 previous to those. So it is "hardwired" to record, it seems, ALL previous tabs activation order.)
When you are looking around for a tab, the 5 gets used up very quickly, then you've lost your original tab!
(Also posted at https://support.mozilla.org/en-US/questions/1219054)