Using a browser interface is part of the point
There are lots of examples where arduino and RPi are used together adding additional hardware to improve or increase functionality is something worth considering
first the basic software needs to be running
If you have followed this from the beginning you can see I changed my mind from having an editable file to store settings to trying to create a web page th put the data in the file
A further addition wood be a drop down allowing the function of each channel to be chosen (simple switch, points, frog switch, variable servo movement, welding simulator, etc, etc, etc)
I would like system that is ease to use