This combines a couple of suggestions 1) note fields 2) Device IDs.into a work-around approach.
Based on:
1) Device IDs show up in Benchmark plots.
2) Deleting a client, them re-adding with a new, unique name, creates a new unique set of records.
NOTE: simply editing the client name won't create a new, unique set of records as it renames existing in Benchmark Viewer.
However, in WU logging, client edits are retained, from my observations.
Thus, if host changes are tracked relative to a unique Client-ID, I was able to achieve the granularity I was seeking with the GPU device ID.