P38 4.6 autobox ecu in TD5?

Have been doing some research into the Ashcroft torque converter upgrade for a tuned TD5 and thinking to make the most of the available low down torque would it be possible to use the autobox ecu from a 4.6 P38 as the shift pattern etc seems to occur at lower revs than with the TD5? Has anyone tried this and would it be a similar idea to going the compushift route?