This suggestion is for a new board display for Cathcart Circle. On the class 314 when it's going the circle the board display would say Cathcart Circle. And at Glasgow Central the P.I.S. would say Cathcart.
Thanks to a modder in a discord server, I discovered that actually the 314 blinds are built in - like the 101, for example. As you see here the Circle displays are included, just not used. As for the station displays I think that would require a re-work of the timetable, as (as far as I'm aware) the PIS feeds from the Timetable.