1st off CORNER WORKERS .. WE LOVE YOU. without your thankless services we don't race. Just hear our side of things too.
Gus, the side fairing # they are refering to would be on the lower belly pan area or on the side of your upper fairing. Im with you, clearly from your photos the single "100" is no less visible than if you had two "100's" back to back on either "side" of the tail. Leaned over, you still can not see the tail from the outside of a turn.
What is a mystery is how for decades we have had numbers on the front, and the tail and occasionally there is trouble, yet all the other sanctioning bodies alllow a single number on the tail. Presently it is actually harder to see some tail section numbers when forced to have 2 of them vs. a single number. The side panel numbers i hope are not enforced except for extrem circumstancs, especially in age of transponders. In the event there is an incident can the corner worker actually get a clear visual on a number every time? With all that goes on especially in multiple bike incidents, or what if a bike is to the outside of the rider your trying to get a number on? Even with a number on the side of the bike (not tail) you still wont see it.
Next we are going to be required to run a number on the bottom of the belly pan in case we are upside down ! (ok... that was sarcastic and sorry , but i have pictures of my bikes upside down..)
ALL kidding aside, i know the corner workers have a hell of a job and it is a less than thankless job for the most part. Rarely do you get a "thanks man, i really appreciate your help today", only rants like this when we riders get our undies in a bunch. Please just consider our view on this too...