I would like to reorganize/rename furniture. But where are the libraries actually used by sweethome 3D 5.6?

Have SH 5.6 installed under /opt/SweetHome3D-5.6/ . Had .sh3f files under usr/share/sweethome3d/furniture . But my changes did not show up in the program.

By now I moved all .sh3f files to a temporary location on the desktop. Yet, Sweethome 3D still shows the furniture catalogue as before - unchanged.

My question is where else can I look? Or is it stored in a completely different set of files?