@Michael: harking back to my comment #10, can you explain the observation that gtk/appmenu suppress all the menubars but only one of them reappears in the "dbusmenu-dumper" output? It seems a bit bogus that menubars can be "lost" in this way. Is some part of the system somehow distinguishing "main" from "subsidiary" menu bars (in which case "ubuntu-local" feels unnecessary)? Or is it just latching onto the first menubar it sees and ignoring the rest?
@Michael: harking back to my comment #10, can you explain the observation that gtk/appmenu suppress all the menubars but only one of them reappears in the "dbusmenu-dumper" output? It seems a bit bogus that menubars can be "lost" in this way. Is some part of the system somehow distinguishing "main" from "subsidiary" menu bars (in which case "ubuntu-local" feels unnecessary)? Or is it just latching onto the first menubar it sees and ignoring the rest?