In the Deferred Technical Preview, items that have MER maps defined in a texture set will have the MER textures applied in inconsistent and unpredictable ways. Other texture files will be visible in the MER map, and the MER map will sometimes be offset depending on resolution. 

In the attached demo pack, lanterns, apples and sticks have been retextured to be plain blue squares, with MER maps that have a border and text written on them in the emissive channel. Lanterns are 64x resolution, apples are 32x, and sticks are 16x. The base item textures are all plain dark blue squares, so any detail on them comes purely from the MER map.

Steps to reproduce:

• Apply the example deferred pack, and load into a deferred-enabled world
• Put the items that were modified in the example pack into the hotbar: lantern, apple, and stick
• Observe them in their held state or in an item frame

Observed behavior: The text from the MER maps is visible, however there are numerous issues. The text does not have high luminosity as it should, the 64x MER texture is offset from the color texture, and other random textures are visible on them - string on the 16x texture, shield on the 32x texture, and bamboo sapling on the 64x texture (pictured in attached image).

Expected behavior: MER maps should apply to item textures in the same was as they do to block textures.