Rolf – actually, neither goes “first”. The Tone TwEQ is an EQ PCB daughterboard designed to provide superior tone control (Low, Mid & Hi) compared to a simple single-pot “Tone” control on a pedal. It can also be used as a stand-alone circuit for better tone control on circuits. (Check out the Tone TwEQ’s build document for more info.)
The Tone TwEQ also has a volume control and you will want to decide if you want both volume controls on the pedal.
The Tone TwEQ can be inserted in place of the the Disturbance’s Tone control. The “In” of the Tone TwEQ can be connected to where pin 3 of the Disturbance tone pot goes; and the “Out” of the Tone TwEQ would connect to the pin 1 location of the Disturbance tone control. And you can omit C8 completely.
You can either volume control from both PCB’s or both volume controls if you like. Personally, I would prefer to omit the volume control of the Tone TwEQ and just connect the pin 3 of the Tone TwEQ’s volume pot (omitting The Tone TwEQ volume pot) to the pin 2 location of the Disturbance’s Tone pot (omitting the Disturbance’s Tone pot. This would give you a “Gain”, “Low”, “Mid”, “Hi”, and “Volume” control on the pedal instead of having 7 total controls on the enclosure.
If you want all the controls on your pedal, then I would put The Tone TwEQ after the Disturbance.
The options are yours to be had.