The main issue I have heard you might have with registering collections (i.e. - "Collected Works 2018") is that the collection is considered a single work, so theft/unapproved use of a single piece from the collection would be looked at by a judge as *possibly* a minor infringement of the whole work and thus *possibly* subject to a smaller penalty. That is the concern anyway.
Also I believe it is generally considered proper procedure to register images within 90 days after publication, so a three-month cycle of collected works might be a better regime to make the infringement target smaller and hit all the legal points for published works.
Britt