Looking for equivalent functionality between dmt and dtui - importing data with id field from JSON into Azure Cosmos

We've started to use the Azure data migration tool since TLS 1.2 support is no longer available in the old Azure documentdb migration tool (DTUI last version 1.83).

What we're having issues with, and can't find clarifying documentation on, is when dealing with the id field in JSON data that we're attempting to import.

Does anyone know what the equivalent configuration is for the Azure data migration tool? (Source is JSON, destination is Azure Cosmos DB).

Example: old DTUI configuration that works:

DMT:

And in Cosmos Explorer for working record (imported after removing id field):

The dmt utility doesn't like the existing id field in the JSON data from the source system and trying different settings in the sinksettings JSON like changing PreserveMixedCaseIds doesn't appear to make a difference. The Cosmos Explorer screenshot is how we would expect the data to look when importing using the old DTUI tool as the partition information is correct and the id field has been auto-populated.

The old DTUI tool handles the JSON fine, but without removing the id field from the records, the dmt runs as follows against the Azure Cosmos DB emulator.