A lot of emphasis is being put on control chain here which is as Falk said completely open-source but admittedly there currently aren’t any available options to buy some control chain expression pedal or adapter which would be very annoying as someone who does not tinker if that were the only option.
Thankfully the device also has a midi input as well as a USB port for midi over USB. We have another thread here (Expression pedals and adapter options for the Dwarf) where we have suggested many available options for expression pedals on the Dwarf.
I can understand being upset that the device doesn’t have an expression pedal input just as I can understand being upset that it doesn’t have any other kind of additional IO. The reality is that you can only fit so many ports and the other ports took priority because they have a broader range of use compared to a port that can only be used for expression pedals. There are 3 other ports on the device that can support expression pedals as well as many other things. This allows more flexibility to the user than a dedicated expression pedal port. The device already had to be made slightly larger than the original design just to fit the ports it has. People have asked for more inputs, expression pedal ports, full-sized din midi etc. While they would all be nice, the device would end up being huge. So we went for the most versatile IO we could fit on a small device