I'll make the same comment I did on the other post about this. Either document how it differs from FreeBSD jails or give it some other name. Anything else is asking for confusion.
That some other name: 'cells' (or 'tiles'), in the compositional sense of leaf and tree, forest, framework is more inviting for creative work than 'jails'.
It would have been more interesting have they released something compatible with Open Container Initiative. Most people use Docker containers and having Docker compatible containers would have helped with improved adoption of BSDs.
I have used jails and I still say it is far easier to maintain, lighter and more secure that what Linux has. The only good thing I can say about docker is it is easier to setup.
Also the way I read the document, NetBSD's Jail is going to be very close to what FreeBSD does.
Could bastille port to it as-is? How about podman?
He wrote things like these are out of scope.
Just light and robust jails without further external dependencies.
IMO anything which makes NetBSD's base more complete is good.
When it is ready, it remains to be seen which external tools may be ported to make use of the newly available internals. If ever.
Also the way I read the document, NetBSD's Jail is going to be very close to what FreeBSD does.