Complexity management is key in any project. Lots of successful forks reduce total complexity. NetBSD and OpenBSD are excellent examples — one could argue that their goals and innovations (in portability and security) would also be useful in the «mainline» FreeBSD, but that would explode complexity.
The FreeBSD community is carefully watching progress across many forks and cherry-picking / importing a lot of the cream.
I’m not sure what to make of it, but amusingly your link says “OpenBSD version of netbsd_hammer2”, which itself says “NetBSD version of freebsd_hammer2”, which in turn says “FreeBSD version of openbsd_hammer2”.
They’re all under the same profile so I think everyone is sharing?
The FreeBSD community is carefully watching progress across many forks and cherry-picking / importing a lot of the cream.