With the current absence of snowy weather the Maestro can come out to play for a while. But there was a strange issue with the Rh brakelight as you can see in the dash cam video I uploaded a while ago. When I checked the brakelight worked fine everytime, But in the video it seemed the Rh came on later while braking.
And indeed, when I took the rear light apart it was corroded and wet inside. This is the brakelight bulb looking nasty and rusty. I decided not to bother with cleaning and replaced the whole unit as I had several spare rh lights in the attic. Now the lights work as intended. I'll have to keep an eye open for a spare Lh light though.