When ibus is configured to start at login, the floating, naked toolbar appears as the first thing, way before the panel starts. This looks bad. The toolbar should remain hidden until the statusicon is embbed in the panel. See the GtkStatusIcon notify::embedded signal
I changed the default value of panel/auto_hide. So user will not see the naked toolbar, if they do not use ibus-setup to modify the default value of auto_hide.
The new release has been built