I "think" the problem for me in Library Manager 2.4 was the hard limit of 900 under 'Options, Data Bindings, Number of Items'.  But it made Library Manager useless for me as a Poser library substitute.  Maybe it would be fine if I broke things down in to a bunch of different runtimes, but I don't want to do that.  The native Poser library doesn't seem to have any limitations like that, at least not that I've run in to.

I absolutely love Library Manager for mass installation of zipped content though.  And it's probably a fine library substitute if you can avoid bumping your head on that hard cap of 900 data bindings.