Well, 252% > 90%  

I see, let me create more reasonable tests. I'm just trying to learn how to use the polar edits feature.

 

I don't see how can I select Tests, just the "Log files" button. 
https://photos.app.goo.gl/8f36xUf57TaPASSk6
There are test visible under Sail->Test menu:
https://photos.app.goo.gl/UMCV6JBKfWbi9Sin7
 

My plan is to have a script where I specify desired brightness and night/day mode. This script will either send it periodically or if it sees that the different value was send from one of the instruments, thus disabling this power button functionality. 

Another way to do it is just physically disconnect the FFC cable that goes from the button to main Vulcan PCB. That might break the warranty though :-) 

For the short coastal races in the San Francisco area they don't use YB, but AIS is now mandatory. So if I want to to use the race tracking feature does it mean that I need to write some piece of SW that reads Exp log and saves the boats info to the format understood by the race tracking import, e.g. GPX?