How about a mod favorites system?
Basically be able to drag and drop, or click a favorites button, to add a mod to your favorites section, per account, while also sorting them into categories and have NMM be able to pull that information up and suggest installing favorite addons when NMM is installed on a system it's never been installed on, once the user has logged on. Maybe also provide a button that lets the user decide if they want the mod manager to automatically start downloading each mod and set in settings to automatically activate the mods if they want to.
That's my suggestion for a feature.
Thanks for your time.