[Gtk-sharp-list] Gtk CellRendererCombo UnGrab on Item Selection possible?

[Iggy]

Why is there no way to unfocus the cellrenderercombo upon selection of
a combobox item? There is only an event for the start of editing, and
after editing, which takes place when the focus is explicitly taken
off the cell. Does anybody know a way to ungrab the cell and trigger
onedited as soon as an item is selected in the combobox?

* And I'm sure somebody will point out some reason why this is bad
practice and how its not supported, but this is what I would like to
do if at all possible.

Thanks!