Ah sweet, yeah I did actually see albatross but wrongly dismissed it as an experimental hack project (I didn’t see/read the associated blog post). Having read the blog, I agree, it seems like [the beginnings of] what I’m looking for - I’ll get it running and see how it goes.
On the topic of Libvirt - I’m curious to know why this isn’t the obvious preference for unikernels given its prevalence and maturity as a VM manager? Is it due to ukvm's superior performance [over virtio] or are there other reasons?