You can disable shadows to items in the config. This also works with items that are an alias since I needed shadows removed from the original item but didn't want to touch the actual item.
Basically the item needs to be at least 4.4 in order to enable the no shadow option and the 'does-cast-shadows' needs to be added under the mesh subcontainer followed by either a 0 or a 1.
Example:
mesh-table
{
default
{
mesh "asset_item.im"
auto-create 1
does-cast-shadows 0
}
}
Setting it to 0 will turn off the shadows while setting it to 1 will turn on the shadows.
Cheers