I've smoothed player movement on a detailed wooden staircase by 'clipping' it all, which now produces default footstep sounds. I would like to keep the wooden sounds but I seem to be unable to. I've tried editing the 'toolsclip' VMT file and set its "surfaceprop" parameter to "wood" (from "default_silent", which means that there is/was support for surface type?), but it doesn't seem to take any effect. I've thought of using an unrendered wooden func_brush entity, an idea I then scrapped right away because it may affect the map's performance and filesize, as well as blocking projectiles and bullets. Is there anything I can do? Though it's not a "serious" problem, I would really like to retain proper footstep sounds.