I wonder if there is some sort of caching taking place. If you start up from a fresh reboot it has to read in all the folders again. If you restart all of these folders are still in memory or in temp files, or maybe in virual memory on disk.

Disks on laptops are not the fastest ones (slow rpm to conserve battery poser), add to that the possible fragmention of folders and it will go slower.

If I start poser from another machine with the library attached as external runtime over a network, it is definitely slower - but nowhere near as bad as you experience. In the case I described above, time to get that last folder filled would take 10-20 seconds. This is on a gigabit network which slows down for small file access to about 100-200mbps. Reading folders is a lot of small reads.

But if the above is the case, I don't see a way to improve that