Changed the filament sensor cover so that an LED behind it shows the status of the sensor. The side walls of the recess are slightly bent to avoid pushing through. There are two versions of the window insert available. The smaller one fit perfectly in my case at the first try. How the LED gets on the filament sensor is very well described in the original by @Mykal451_7969.
Happy printing
The author remixed this model.
Added reverse bowden option.