I avoid socket OCD by just cutting pieces of PVC pipe to fill in the missing tray slots. That allows me to not have to buy every socket size while still being able to glance over my socket racks to quickly see if I forgot to put something back after a project.
The PVC pipes that have end caps dropped in the top that say "HAVE" are sockets that I do own, but they are either a part of my travel socket set or are stored somewhere else for convenience purposes.
For specialty sized sockets, one-off sockets, or sockets that do not have a space in a socket rack, I just drop a PVC end cap into the socket and write the size on it for easy identification. I have other sockets that i don't have pictures of at this time, but the last picture shows two examples so you can get the idea.