Question

There are possibly more subfolders in outfits/ than shown. Only the first folders whose names don't exceed 1023 characters are shown

This bit of yellow text is harmless but driving me insane! Whyyy... I don't have any folders with absurd long names!

Answer 1

It's not about individual folders with long names, but it appears when the entire list of all folders you're wearing items from exceed 1000 bytes.

This is because chat messages in SL (including the answers from RLV, which are also just chat messages), cannot exceed 1024 bytes (1 KiB).