This looks pretty decent actually. Sure, you could consider it a frontend/SDK for bubblewrap/seatbelt/processcontainer; but setting em up consistently is far from trivial; and hand rolling is a really bad idea (speaking from experience).

I like the ‘learning’ mode for figuring out what perms/config a runtime needs, the MIT license, the clear optional telemetry disclosures, and somewhat light and still readable documentation.

Regardless of your views on Microsoft, this looks quite useful; serves a clear purpose, and from a quick glance, looks like a high quality project even if it’s just the first version.