bcantrill, In the conversation that @ahl and I had with @jmc last week, we talked quite a bit about RFD 26, which explains the rationale for Helios and Propolis, our illumos-based host OS and bhyve-based hypervisor, respectively. By popular demand, we have made that RFD public:
https://rfd.shared.oxide.computer/rfd/0026
And if you didn't catch the conversation last week, you can listen to the recording: