Sent the observation and the sign idea through DriveTest's customer service form. Got an auto-reply with a reference number and a note that feedback is forwarded to the centre manager. I'll follow up in two weeks, and in the meantime I'm asking two driving instructors whether they see the same confusion at other centres so this isn't about one location.
Timi Tejumola
TejumoladavidDavid Tejumola
Jesus Revealed Jesus Glorified Foundation
Timi