(01 Feb 2021, 4:33 pm)ne14ne1 wrote London uses small letters on Night & Express services but their destinations are much clearer being either blinds or digital paper screens, along with having the numbers to the right, no via points, and maybe often approaching at slower speeds too:

The revival of this thread has prompted me to suggest that you may be on to something regarding the London layout. That's if we take the second comment on the linked photo as the company employee that programs all of the displays and not as the enthusiast making a comparison. 
Go North East: 6363 / NK70BYN | Daniel Graham | Flickr

Wider context of Dan's response is in regard to the double height display, but the offside route number and smaller variation letters are also featured.

Worth re-acknowledging the MD's argument that having the number on the offside reads better so it doesn't seem as if I'm suggesting that all of the changes made have been done purely because it matched what bus operators in a city ~280 miles away do/used to do.