The most "research" thing I'm aware of 9front (since you're speaking in present tense) doing is that GEFS needed to work out a lot of things for itself that weren't in the Bε-tree proof-of-concept FS that came before.
I dunno how "close to the metal" you'd consider that.
("GEFS" being a disk filesystem that's been discussed on HN.)
"Plan 9 praisers who don't actually use Plan 9" have a tendentious way of speaking, that's actually a lot like "AI slop", that Plan 9 users can instantly recognise. Telltale signs include speaking about Plan 9 in the past tense, and a belief that with Plan 9 you can somehow just strap all your computers together to get more performance or something. Because "you have 9P".
I dunno how "close to the metal" you'd consider that.
("GEFS" being a disk filesystem that's been discussed on HN.)