Brief update:
I spent 5 days off and on experimenting with single and multiple drum cymbals in in between the speakers, at first reflection points on the sides, and behind me. I even put one at the exact height of the center horn on my speakers in between them, on a cymbal stand with the bottom of the cymbal facing my listening position.
My conclusion was that the very first thing I tried was the best. That is a 16" medium crash cymbal sitting on a wooden plate display holder on top of my CD transport, which is far higher than you would think would be its most effective position. It is 59" from the floor to the center of the cymbal, while the distance from the floor to the center of the horn on my speakers is 35".
In this position, there is a very noticeable effect, but it's hard to describe. I would first describe it as more presence, but it goes beyond that. There is no sense of ringing or overhang, quite the opposite. Things seem smooth, but more focused. I still can't really put my finger on the description of the effect, but it is very positive for me, and I am leaving the cymbal in place. I will say that the effect is plain enough to make it audible from another adjacent room.
I want to state again that I don't think that this is a drop-in replacement for the Novum Resonator, although I have never heard one, I'm sure it's probably much better. Still, it was nice to find out that something that costs a small fraction of the Novum is also effective in improving the sound of my system.
I think if you have a friend who can loan you a cymbal, you should try it. I want to mention that I also experimented with single and doubled hi-hat cymbals, which were smaller but heavier, and the effect was not as pronounced or as pleasing. I did not try a large ride cymbal.