You can use the multiple exposure mode on the Z cameras and set the mode to “lighten” to get a similar effect as “live composite”:
https://www.nikonusa.com/en/learn-a...ade-easy-with-nikon-z-mirrorless-cameras.html
That multi-exposure mode has nothing to do with the Olympus and Panasonic Live Comp. While the Nikon camera only allows 10 exposures, Olympus allows thousands of exposures, as many as the battery allows which usually lasts a few hours. In the end there is only one raw file.
Another interesting thing about LiveComp mode is that you can see the final result of the photo on the screen at the same time it is being taken so you can stop the exposure whenever you want. Thats is also possible in Olympus Time / Bulb modes.
A shame that is only possible in M4 / 3 cameras and Huawei phones