Hello! Yes, repo'd items can be made to show in collections only. When you say categorizer, do you mean the old version by Paladin or are you trying the new Object Relocator by whoward? If the former, try the latter. If the latter, maybe send whoward a message on tumblr about the crashing.
Someone on Discord actually was getting errors when doing this, making poseboxes catalog only. However, I don't know if it was because of the process or because too many packages were loaded.