Hi,
Having just installed the new April 2024 software update for the GS911, I have been working through getting the central rear Brake Light to remain on and also act as a rear Marker Light.
My 2021 1250GS is fitted with the original full Weiser Technik Indicator replacement set that I'm very pleased to have, rather than the previously fitted BMW system.
If you also have the full Weiser set up, then just to let you know that for the central rear Marker Light to have a similar intensity to the normal Marker intensity of the Weiser Indicator / Marker / Brake lights I had to set the central Marker Light intensity to 50% rather than the GS911 suggested 10%. Not doing this made it appear as though the outboard Marker Lights had stuck in the Brake Light intensity.