I finally finished my ornaments for everybody in the family. Used proofgrade walnut with proofgrade maple as the insert material. The maple was sized up to account for the kerf and everything turned out great. I did spread wood glue on the back to make sure everything stays in place long term.
A few things I learned that may be useful:
Deepnest was very helpful to save material (it took 2 sheets of proofgrade maple for all of the inserts)
Don’t put all of the inserts from all of the ornaments together on one sheet. It turned into massive and frustrating jigsaw puzzle that took me about 4 hours to place everything.