Hi Doug,
Thank you very much for the kind words! We are excited to hear that you are liking it!
@kulin_seth and his team develop the Metal plug-in 41. (They have worked really hard for the release – Kudos!) He can help answer your question. 
Best,
Penporn
P.S. We have changed the tag of this thread from tfdata to pluggable_device just so it’s easier to look up all PluggableDevice-related posts.