Major advantage of using external libraries for all but the most 'core', frequently used items is so they do not clutter Poser's in-house run-time folder tree, may be easily culled...

My 'as required' external libraries are spread across three big drives, 1TB E:+ F:, 4TB G:, would be utterly unprintably unmanageable were I to stuff contents into Poser's Runtime on C: Besides, they simply would not fit...