In the equipment profile (selecting the G40/G70 card in the equipment page), you can toggle the "Boil power control" button.
This allows you to change the boil power once the brewing has started and the controller is in the Boil stage. You can also set the default % on the equipment profile.
The "Boil power output" value you set in the equipment profile serves as the default starting value when you reach the boil stage during an actual brew session. You won't see any effect when testing manually outside of a brew batch - it only activates during the boil phase of a recipe run through the app.
When you start a brew via the app and reach the boil stage, the G40/G70 will automatically set the power to your specified percentage (e.g., 95%), and you can still adjust it up or down from there using the controller arrows as needed.
One thing to note: the boil power output setting isn't currently factored into the app's boil loss calculations, so you'll still need to manually adjust your equipment profile's "Boil loss" value to 4.5L/h based on your actual results.,