Aye, it's actually been a problem since Bryce 3D, when they first started implementing this file/library structure. Even worse is the way Bryce will randomly "smoke" your whole folder, for no apparent reason, whenever it gets "too big". Although nobody has actually tested out what "too big" is, and methinks that it's not a size issue at all. Presently my Bryce "Presets" folder is at 1.93GB, with 1.03 GB of "User" objects... And no crashing, no problems with it all disappearing. So this leads me to believe, again, that it comes down to how Bryce saves and loads these .obp's, which are just about the stupidest file-type ever. If DAZ ever did anything right, they'd allow import-only for the .obp's, and convert everything to .obj's internally. But then again, how would they go about keeping Bryce's light system, materials, and curves in place? Methinks THIS is the real reason Bryce doesn't export anything, as opposed to Metacreations slacking off back in the day. It's a great question, "How would we export the lights and materials, too?" But, they did it with the terrains. So we know it's possible!