Steven:
I don't know if having the MEP add on makes a difference. There appears to be 3 parameters for the waste connection (
ConPosX_3,
ConPosY_3,
ConPosZ_3) in the library part, with the first 2 controlling the plan position of the drain in the 2D Symbol. These parameters are hidden. You could open the library part and unhide the
ConPosX_3 and
ConPosY_3 parameters so you can alter them. I don't know what other consequences there are if you are using MEP, but this should be OK if you are just using the tub as a stand alone object. As usual, you should Save As... a copy of the part for editing.
HTH
David