Improvements and fixes to illumos bhyve are almost entirely done in upstream illumos-gate, rather than the Oxide downstream.
Upstreaming those changes into FreeBSD bhyve is a more complicated situation, given that illumos has diverged from upstream over the years due to differing opinions about certain interfaces.
Yes, my personal goal is to ensure that basically everything we do in the Oxide "stlouis" branch of illumos eventually goes upstream to illumos-gate where it filters down to everyone else!