Have you tried Calibre?

$999
I have no use for a HR smart watch but at this price it’s not even a possibility. Hundreds of dollars is acceptable but this is a hard no for me. My Casio G-Shock GBD 200 + GadgetBridge has all the features I want from a smart watch and costs about $150.
However, I will say kudos to Masimo for sticking it to Apple. Not many people can go against a giant like that and win.