"There is a discussion because not everyone agrees with you."
No, you are confusing the intention of the thread (discussion about the exterior surface markings) with the detour it has taken (identification of a surface structure, whose function has been abundantly established in the original and un-revised series)
Fact # 1: The light bulb wasn't there on the pilot episodes VFX (Pike-)Enterprise model. When the model was altered, i.e. lowering of bridge dome, removal of yellow airlock platforms
near the port and starboard running lights on the upper side of the saucer (back to the original thread for a second) and design change of the warp engines (e.g. addition of the spheres to the engines' aft) this particular light below the flight deck's starboard side was added.
Fact # 2: In every
shot where Kirk's original
TOS Enterprise (the one with the warp engines' spheres) makes a pass in front of the camera that allows a good look at the bulb's location, you, me and everybody else can clearly see that this light bulb turns on-off-on-off etc.
I therefore think it's pretty fair to conclude that we are looking at a running light because everybody who is not blind should have the ability to see it.
(I should also add that in most other shots of TOS-R there is neither a bulb or
a flashing light at this location)