This is somewhat related to ISO - AircraftID (additional attribute) mapping to actual Aircraft. I have implemented our ISO to write it as mentioned in that thread and in the mapping spreadsheet, and the AircraftID does indeed seem to be getting passed into the UMM-C and ECHO10 as expected in the Platforms. However, it still seems to be having problems getting a proper Descriptor Maker file. In doing some digging, I think the problem may be that the Descriptor Maker is looking for an "AdditionalAttributes" section in the ECHO10 (and soon in the UMM-C). We are currently writing the SIPSMetGenVersion, which gets put there, but the AircraftID is not.
Around row 285 it talks about the "AdditionalAttributes/AdditionalAttribute" section of the UMM-C, and says it looks for the mapping to come from the dataQualityInfo...lineage...processingInformation section of the ISO. While this makes sense for SIPSMetGenVersion, as that's related to processing, it doesn't really make sense to have it write the AircraftID attribute information there. There is a note at V285 that seems to indicate the same thing, that there are other ISO mappings that should also be put in the AdditionalAttributes/AdditionalAttribute section of the UMM-C/ECHO10.
I just want to make sure I'm understanding correctly, though. It feels like this may need to be a ticket for an update to CMR. In this case, it would read from the ISO's Platform/otherProperties section, and use that not just for the specific Platform attribute (which it's currently doing), but also use the attributes it finds there and put them in the top-level AdditionalAttributes section.
I hope that makes sense. If not, let me know and I'll try to put a snippet of ISO together.