Yep that's quite likely... Maybe one day I'll revisit it.

Just a thought about the Schottky diode note giving an improvement over the 1N4007.

Your article stated that the power supply's output was approximately 110V. Do you suppose that the Schottky was leaking heavily or even breaking down because of excessive reverse bias?

Hard to otherwise imagine other ways a Schottky would not give improved performance over an 1N4007 in any high speed circuit.