I'm somewhat confused. In the "official" 1.1.0 will items disappear after you nano them 15x, or are you saying that's the way it used to be on "live servers" and you're making this mod to bring your SP experience more in line with what MP used to be?
As a side note, anyone wanting to only reduce vendor and crafter refresh times can use HGLModder to set the Game Globals for "merchant_refresh_time_in_ticks", "merchant_refresh_required_time_between_browse_in_ticks" and "craftsman_refresh_time_in_minutes" all to 0 for Data 1 and Data 2.