The Freestyle 2 for Mac has working multimedia keys, which double as F keys when you press Fn - basically to mirror standard Apple keyboards. Unfortunately there must be some internal hacking involved, because the Kinesis does not respect the System Preference for swapping multimedia with F keys; I was hoping to work around that with some app, but nothing seems able to intercept most of its multimedia keys on Sierra. Tonight I'll try with khd [1], if I can figure out how it's supposed to work...

[1] https://github.com/koekeishiya/khd