There's been no recent research as far as I can tell.

The studies last year looked at how long SARS-Cov-2 existed on differenet surfaces and noted that the aerosol droplets could no longer be detected after 24 hours. This is pretty consistent with other aerosol viruses.

Besides that, after a lull early in the year, package deliveries have progressed pretty much unabated last year and there were very few reports of coronavirus cases from unknown sources (which I would include packaging contaminants within)

I should think that ordering a package from Nevada will be a pretty safe bet. And if you wanted to be extra cautious, you can handle with gloves and with a surface spray (or any other way that minimises your contact)