Tom, service mode is the ONLY condition where you do not NEED nor USE the address of the loco... Service mode is defined in the NMRA specification...
yes many command station/booster combinations can switch a track output to service mode from the normal mainline output, as opposed to haveing a dedicated program track output (which only does service mode)
When you enter service mode, there should be NO requirement to enter the address to use it... yes you can set the loco address while in service mode, to wit: short address, long address, consist address.....
BUT the USE of service mode does not REQUIRE entering any address, which I have said consistently in this thread.
again, I have trouble with this statement of yours: You should be able to then activate the loco on your programming track with your Navigator by then using the Address you just set..
the "programming track" is a bad term to use, as many people will associate the MODE of communication with the physical track.... not the actual process of entering service mode
when you say activate the loco on the programming track, you have stated before this is service mode....
you do NOT use any address to "activate" a loco in service mode... service mode will talk to all CV's irrespective of any address in the loco...
This is why I continually counsel to use the terms "in service mode" which is the NMRA wording, or at least "in programming mode", but even that is dangerous as people can program on the mainline....
I just encountered an issue with some friends developing the BlueRail system here in the US and they were having all kinds of issues that made no sense whatsoever.
I found out that the developer had issues with reading CV's and really service mode, so when this system is in "programming mode", it actually WRITES CV's with POM, Programming On the Main, but it reads CV's in service mode, BUT it can only read a few CVs, and it NEVER writes CV's in true service mode.. and it will not read CV29 correctly....
So they had a loco where they read CV1 and got 3, and tried address 3 and nothing worked.... it turns out it was set to a long address, but since they could not read CV29 (nor 17 or 18) they had no idea what was wrong, making the erroneous assumption that short addressing was enabled when it was not.
They blamed the decoder.... I have encouraged them to make service mode work properly, but they think they can avoid this need by hard resetting a decoder, forcing it to short address 3.... what a mess!
So, maybe this helps illustrate why I can be a stickler for what is REALLY going on, and keeping the terminology straight... they had a programming mode, but it was NOT really service mode... on all CV's....
Greg