My third Z camera, a Z6 modified to be "full spectrum", is on its way. It safely crossed the Atlantic in a minimum of time. However, for now it is stuck in Norwegian Customs and the upcoming Easter means there likely will be two weeks yet before they release it from their firm grip. After slapping a healthy amount of VAT on the shipment, of course.
Meanwhile, being grounded myself by an unfortunate car accident, I experimented with my current Z cameras to learn how effective they protect against any UV entering their sensors. Mounting the UV-Nikkor 105mmf/4.5 with the Baader U filter on either Z6 or Z7 does allow visual focusing even through that dense filter. Well, provided there is full daylight and finder illumination is increased from the zero setting. Still just enough to do manual focusing with the unmodified stock camera in UV.
I did some hand-held UV captures with the Z7 for fun, besides to learn how effective UV is suppressed by the stock sensor. Apparently UV is kept down at least 8 EV even when using the specialist UV-Nikkor lens, implying unwanted UV is very unlikely to be an issue for ordinary shooting.
Here is an example shot at f/4.5, ISO 25600 and 1/6 sec using the UV-Nikkor on my hand-held Z7. Not very exciting except for proving UV can be pushed through almost any optical system yet there is no guarantee of any final image quality.
Oh well. Back to waiting for the Customs to release my UV/IR Z6.