Hi Tia, sorry for the slow response.
The source code is available on GitHub here: https://github.com/nootropicdesign/defusable-clock
It is possible to change the functionality and add features, but the kit is a much older product than the newer Game Timer Pro with all the features. It’s not easy to program embedded software, so I wish you luck, but I wouldn’t be able to help you. The reason I produced the Game Timer Pro is to incorproate all the features that so many people wanted.
I’m not sure what vias you are referring to. All features of the board are described on the product manual page: https://nootropicdesign.com/defusable-clock/
Have fun!
-Mike