Yes, you can do it.

BTW, I made props, morph and even conforming clothings for Poser or DAZ|Studio using Blender 2.44.  I just upgraded to 2.45.  Please use .OBJ format only.

For making morph target, make sure "Morph Target" button is selected, otherwise your morph may not show up properly.

Note that 1 Poser unit is about 8 feet.  Therefore, the cube with 1 unit in length in Blender will be bigger than most of the Poser characters in Poser.

For morph target or clothing, I do not  change the scale of the input and output to avoid rounding problems.  For props, feel free to use your faviorite measuring system in Blender, I use 1 = 10cm in Blender.  When you export the OBJ, you can scale it to the Poser's scale.