This is pretty close. The miles are banked and after a certain threshold is reached X amount of power is delivered to run off time.
In most service units (most, NOT ALL) it doesn't matter whose power is in the lead. Here in the Fort Worth SU we routinely ran CSX, BNSF, and NS power on the nose. BTW, even though it may be a UP train we still radioed as BNSF (or whatever power it was) XXXX (road number) to dispatch. Now, in some SU's, you had to have home power on the lead due to in-cab signaling or some other requirement. But you also need to make sure that you have a functioning Harris Box if DP'd and make sure you had telemetry to the FRED. FYI, UP uses air driven FRED's and BNSF uses battery powered. FYI again, FRED's are required because you have to be able to "plug" the train from both ends now. That is one of the tests that carmen (or conductor is no carmen) have to check prior to signing the air slip (except for transfer trains).
But, don't give the RR too much credit. As a whole, UP can barley get up in the morning and get their pants on. There really is little thought as to what power goes where. No one cares whose road, which way it's facing, or even if the thing has been serviced or not. UP is absolutely horrible (in the FTW SU) about servicing power. No ice, no water, no toilet service, no wash, no windshield, no sand, etc. If you don't want to go it'll only take about two minutes to find an FRA no-go item. Call the service track and refuse the train. As soon as the RR started denying claims I started refusing trains. You can beat them over the head with the rule book all day long if you know it and never turn a wheel.
BTW, I preferred BNSF power every day of the week and twice on Sundays. Their equipment is so much better maintained. The worst was former MOPAC. Their units had half back seats that were impossible to recline in and get comfortable. The only thing worse than an old MOPAC was a GENSET.
Sorry for the general rambles, just some FYI stuff.
Macjet