Prototyping DIY Expression Pedal interface for Kosmo

The only reason to lower the values would be to lower the output impedance (i.e. make your pedal able to source more current into a low impedance input without dropping too much voltage, cf the discussion here). I’d consider adding an output buffer instead so you only use more current when you actually need it, alternatively making sure to always route it via a high-impedance input (haven’t watched the entire video, maybe he does that?).