The old plugins list allowed us to see that of X number of sites (our search group) there were Y sites without the plugin (or theme) and we could sort by which sites had said plugin or theme. I have not found an easy way to do it with the updated search
Negative search does actually return what you are looking for, which is the sites on which a certain plugin is NOT installed, but due to the fact that the table was changed in v4.3 and is now grouped by plugins only, it may be a bit confusing.
When you perform a negative search, you will get all plugins that are installed on child sites that do not have a Negative search plugin installed.
You can then mark all those plugins and then click the Install to Selected Site(s) button, which brings you to the Install Plugins page, with the relevant child sites already selected in the Sidebar on the right.
Thanks, Bojan, that is already useful. Are there plans to un-confuse this process?
At least, like this I can already see where that plugin isn’t installed. My next question was how to install my plugin to those sites. But I see there are small print links that allow me to do that.
Unfortunately it gets even more complicated: I use two plugins for the same purpose and need to find the sites that have neither of those installed. The plugin search has no AND or OR, does it?