Are Kiwis ready for the Cash Cow? 
I think the issue with the extra bulletins was they either aired at awkward time slots or were on multichannels that no one watches. Plus they weren’t well advertised. No wonder they flopped.
What they could have done instead was turn Three itself into a rolling news channel during the day. From AM Early at 5.30 through to the big one at 6pm, just keep it going all day. As you said, they had CNN, 7 News, ITN all to rely on for international reports. Pad out each hour with some interviews and just keep it flowing throughout the day. Maybe some ITV/7 News bulletins during back half hours. Overnight they could either stick with informercials or relay CNN.