the ruling on interdimensional matter transporter[IMT] and snatch steal/change of heart/enemy controller is:
if you control your opponent's monster by either of those methods, then rfg it via IMT, it will return to the game, then immediately return to your opponent.
i imagine the ruling would be the same if player A were to control player B's monster via dark necrofear, then player A were to IMT it.
or any other type of "temporarily take control of opponent's monster":
brain jacker, brainwashing beam, dragon manipulator, falling down, jowls of dark demise, mind control, rafflesia seduction
if you control your opponent's monster by either of those methods, then rfg it via IMT, it will return to the game, then immediately return to your opponent.
i imagine the ruling would be the same if player A were to control player B's monster via dark necrofear, then player A were to IMT it.
or any other type of "temporarily take control of opponent's monster":
brain jacker, brainwashing beam, dragon manipulator, falling down, jowls of dark demise, mind control, rafflesia seduction