I’ve been riding the Shimano GRX Di2 RX825 groupset for the past eight months or so, and while there certainly are some drawbacks to the groupset, I’m surprised to find that I’m in no hurry ...
In this case, Shimano went off book with their DI2 groupset, leaving [kwakeham] with a reverse engineering job on his hands. [kwakeham] gives us a great example of how to approach reverse engineering.