It’s not really an issue yet but over time I could imagine a lot of objects will start to fill up the imported items folder. Even buying to many bundles from the market place might slow the search function down a lot.
I was trying some random bits of wall textures to get it just right for a temple I was building and now I noticed my imported items selection growing. Some of them were just plain ugly and I really don’t think I would use them again, other items I might rarely use again but would appreciate removing them from normal searches.
Far as I can tell though you can’t delete any asset in the imported section and there is no archive option to put something into ‘storage’ of some kind without it turning up in searches. If either of these functions are possible it would be great. Not an immediate problem, but over time most users would start to rack up a lot of files with no option to remove them.