Some L1011 pilots used centre engine thrust to obtain the perfect number of stab trim units required for various performance targets.
About half a throttle knob was usual and got the nose down and the pitch attitude required for a stable cruise speed with range.
I was told by Lockheed that the hull section seen nose to tail, provided signifigant lift and therefore the pitch attitude in climb and cruise was important.
411A has a vast experiance of the L1011 and could provide valued input on the above.