Last night I took some time and made some experiments and here's what I found: the volume bump is no lo longer an issue as soon as I use the TimeFactor in mono in/mono out operation. It was a problem when both inputs were active on the TF (although both caryying a dry, identical signal coming from a bypassed DD-7 in front) and only one output was used (Output 1). In the TF manual they elude the stereo in/mono out scenario, maybe the pedal is not ready for that. So all I had to do was simply unplugging the cable going into Input 2 of the TF and, voila, no longer volume bumps.
