I think the scrolling nature of the displays doesn't help. Say for one of the Royston village splitters, the message you want to get across is:
All 8 carriages for Letchworth, Baldock and Royston
Front 4 carriages for Cambridge
Rear 4 carriages for Shepreth, Meldreth and Foxton
But what you get is:
11a Cambridge: Letchworth, Baldock, Royston, Cambridge.
11b Foxton: Letchworth, Baldock, Royston, Shepreth, Meldreth, Foxton.
I'm not sure how to put it better, but the latter isn't at all clear for the occasional traveller, particularly if not all the information, or information about splitting, is on the screen at one time.