I don't agree. over 4000 messages on the list, so clearly, splitting these out individually producing what? 20K+ messages? not what you could record properly in

I don't agree. over 4000 messages on the list, so clearly, splitting these out individually producing what? 20K+ messages? not what you could record properly in a single day with concentration, breaks etc. If you look at the examples, they record them with different emphasis so they can appear in different positions in a sentence and sound natural enough that you can hardly notice. In the last 10 years, I don't think I have heard any of these in the UK that sounded like you describe. We all know the voice is a robot anyway so as long as it is understandable, it's fine.