Android's sideloading limits are its most anti-consumer move

We need to stop calling it "sideloading", we should call it freely installing software. The term "sideloading" makes it sound shady and hacky when in reality it is what we have been able to do on our computers since forever. These are not phones, they are computers shaped like phones, computer which we fully bought with our money, and I we shall install what we want on our own computers.

If Google provides a permanent mechanism to disable this in developer settings, then this devolves to an inconvenience.

The setting to allow unsigned apps could be per appstore tracked by an on-device sqlite database, so a badly-behaving app will be known by its installer.

Have you read anything about this? What you are proposing is exactly what is being disabled.

Let's say that Google implements this restriction, but allows F-Droid a permanent permission to disable it for apps installed through their store.

Then there is both increased protection and accountability.