I own the VR-4 HSEs driven by JC-1s as well, and have preferences in music that are similar to yours.
After living with both single wire plus jumper, and a bi-wire setup I find that the soundstage is wider and deeper, and the presentation more open and dynamic when bi-wired. I'm using Ridge Street Audio Poiema bi-wires, which are also fast and open, but have more weight than your Au24s.
I think it would be worthwhile to continiue experimenting with different spikes. The narrow body 1.5" Audiopoints helped to increase the transient response/speed and overall coherence of my VR-4s These were a big improvement over the slower sounding 2" Audiopoints I originally tried.
I would also recommend plugging each of your JC-1s into a dedicated 20 amp outlet. I haven't done a lot of back and forth comparisons, but did notice a slight softening on complex transients when two JC-1s share the same 20 amp outlet.
One other tweak, albeit an expensive one, is to sit your JC-1s on Sistrum SP-101 platforms. These help to produce a very balanced and open presentation, with great detail and extension. No leaness or lack of weight as rpl... suggests, and they do make the soundstage taller.