This makes an interesting read:
https://techcrunch.com/2016/05/03/wh...-making-sense/
It says that ten years ago, TiVo was hardware play and now it's regarded as software play.
When TiVo made the hardware and put their software onto them, I bet they were excellent machines, but now they seem to licence their software to any old box.
I think that the problems with the VM TiVo, therefore, do not lie with the TiVo software itself, but the crappy box that VM have used to run it on.
Had TiVo made the boxes, things would be a whole lot different.