Given all the information that's now available to fans at a track (live timing, big screens etc) - is being able to see a driver number even that important anymore?
Yes.
Just consider how often Crofty mistakes teammates for each other. If you’re lucky enough to have live timing at the track, you still have to confirm what you’re seeing in front of you is what’s shown on the app, and the big screens suffer from the same problem viewers have at home. You cut to a car and if it doesn’t immediately have a graphic on screen, you have to figure out who you’re looking at. Sometimes in qualifying there are up to three names with timers on screen, so how do you know who you’re watching?
The worst one is when you see a car having had a major accident, and you want to instantly know who you’re looking at, out of concern for the driver.
I don’t think there’s any reason to not have instantly recognisable markings on each car, so you don’t have to refer to something else so work out who you’re looking at. This applies to even the most casual fans.
Large numbers in contrasting colours on the nose and on the sides (be it engine cover, side pod or wing) cover that requirement easily.