Edit list

[Starbuntu]

How can I place a new entry on last list position?

[Starbuntu]

That's a bit tricky:
First place the entry as second to last, then insert (copy) the last entry as third to last and finally delete the last entry.
Easier way:
After inserting the new entry change the entry sequence in the source file in ~/.config/gtk-3.0
Good luck!