I know I am always saying, “just spend the money!”, so here I go again. The latest version of
Lightroom has a very wide variety of Nikon Z7/Z6 camera profiles, both color and monochrome, in addition to the usual Adobe profiles to apply when importing and converting. I have found these to be something of a godsend, hugely useful, and have made the subscription more than well worth the money. To me. (I am not going to argue that subscription models are not immoral or gouging, that’s been done to death, only that what is available in up to date LR in terms of RAW conversion isn’t exactly available anywhere else, and it’s good. And, over and above the available importing options, LR has improved significantly since LR6 as well.) If Adobe has trial periods for LR (don’t know) that would be worth at least trying before digging one’s heels in. Those are expensive cameras with great sensors, worth exploring what’s out there to get out of them what they are capable of, and not every software will do that.
Needs mentioning that if one, understandably, doesn’t want to pay Adobe for up to date software, the other available best option is Nikon’s own RAW conversion software, NX-D, though, since it’s free, it carries the stigma of seeming like it must not be worth anything.
Nikon, unlike some other companies, doesn’t release the algorithms which run their camera processing engines to anyone else (boo, hiss) so Adobe, Capture One, everybody but Nikon, have to reverse engineer to make their Nikon conversion software. It’s a guess, sometimes a guess we may love, but it’s a guess. Many (smart) people use Nikon’s NX-D because it is the only conversion software which is made using the proprietary information Nikon has about the science used for their own files. You want Nikon colors, NX-D is the only thing that knows exactly what those are. Excellent results are possible, some people claim them to be the best possible. But, it’s a bit funky in use if coming from something else. Perhaps. Excellent and free, and makes sense after you have used it for a while. Did I mention that it is free?
Best of luck regardless, nice cameras.