Often there is a need to quickly find which packages have been installed by the user.
Especially when one package installs a whole bunch of dependencies.
At minimum, it should be possible to quickly distinguish between packages installed in the factory image and those added by the user.
Secondly, it would be to be able to list package in order of date of installation.
This is most pressing when one recently installed package is causing trouble but you're not sure which. It can be easier to just uninstall any recently installed package in reverse order of the date of installation.
I think it really is a basic quality of life feature for a package manage to be able to tell you date of installation of each package and the ability to differentiate for distro packages and user packages
It is a very basic debugging step to "try uninstalling the last couple things you've installed" when a problem arises and I think the package manager should help with that.
After the reboot, look in overlay and note there's nothing there, yet you still have all of your "user installed" packages. If you check the install dates on a bunch of stuff, you'll see they are identical to all the base installation files.
There's real difference between packages that just happen to be in an arbitrary .img and ones you opkg install at some later date.
For example, do a fresh install using current SNAPSHOT, which does not contain LuCI. If you opkg install luci, does that make LuCI a user-installed package, or is it part of "base OpenWrt"?