It is difficult to imagine how a registration scheme could be enforced for any small electronic devices in this day and age.
An invention known as the internet has made it possible, no commonplace, for individuals to import goods directly from the far east one unit at a time. The vast majority of companies satisfying this demand are more than happy to lie on their customs declaration and claim any contents are a gift of less than $5 value, or to falsely claim there are no lithium batteries included in the shipping documents, so relying on the seller notifying an authority of sales is a non-starter.
That means any registration scheme would have to rely on the purchaser notifying the authority of their purchase after the fact. If you were a wreckless drone operator, would you register?