Davidfor, thanks, I'll give it a try when I purchase a Kobo.
Still, given the amazing array of flexibility and poweruser settings available on the Kobo, along with the volume of complaints regarding the wasted white space (
firmware hacks to remove whitespace), I still think that Kobo should add this setting to the firmware.
(My old Nook STR hasn't needed any settings to handle widows/orphans without wasting white space)