I am pretty sure you can not work with anything less than a full pixel in Photoshop if you are talking about the axis settings those get rounded up or down and the object is shifted accordingly. If your object has feathering this will be affected by the .23 but it will still use a full pixel not a partial one.
I don't know where you would be seeing partial pixel sizes for the document size though...
The top is with no pixel snap setting and the bottom is with a pixel snap setting. Without it the partial pixel gets feathered.