A bit of confusion here. "Track-up" and "Heading-up" is a feature of the ND and is airline specific and can only be changed by engineering, i.e. on the ground. Boeing provide a switch on the instrument panel marked "True/Mag" which is switched to "True" to allow navigation checks after waypoint crossing (OTS) and compares initial true track (ITT) against actual track on the ND. An airlines' SOPS may recommend selection of "True" for the entire track crossing, while some airlines may not. The use of "True" is important in high latitudes due to large magnetic variation.
Having operated B744s with "track-up" and others with "heading-up", either is simple to get used to - the important usage is for navigation accuracy, as LNAV will only track what the user inserts into the FMC.