When you switch to the katana while in build mode, after a few seconds it will play a sheathing sound despite not having any visible sheath.

That's because the "Filter Animation" option doesn't mean removing all epic fight logic from the player. It just disables animations so that other mods using animations could be compatible.

That is fair, but perhaps the sound for sheathing should be muted while in build mode, since there's no sheath?