Out of sheer curiosity, I wanted to see if I could at least get into the test menu for Virtua Cop 3. Did I? Yup, I sure did.
Aside from the fact that it looks rather bad (it's because of a render target issue, causing the primary colour buffer not to be cleared properly AFAIK), it does work and I can change the settings and what not. How did I do it? I simply ran the vc3_t.xbe which takes you into the test mode. That .xbe doesn't do much except pass along some parameters to tell Virtua Cop 3 to start in test mode. Cxbx saves those parameters to disk as CxbxLaunchData.bin and loads it during the next call to GetLaunchData. If VC3 doesn't find this data, then it will just try to load normally. Trying to exit and resume normal loading will cause a crash unfortunately. A call to RtlEnterCriticalSection that crashes when it calls EmuSwapFS is something I've never figured out how to fix as there are a handful of games that do this.
Still haven't worked out the problem with JVS not being recognized yet. Just thought I'd share that since the Cxbx news front has been getting silent lately.