I'm an OpenBSD user, and while that's a solution, it's not a good one. The poster is right, lack of a modern filesystem is a major shortcoming of OpenBSD; but sadly nobody with the right skill set has decided to work on that.

If I remember rightly there was some interest in porting HAMMER2 (DragonflyBSD's filesystem) to OpenBSD, but it's a lot of work with very few people both interested and experienced enough to put in the work.

Sure, or just roll a tar-ball etc. It's how to do it. It's just a bit of a round-about way, is all.

Yes. But most OpenBSD system partitions (anything but /home) get a pretty small size compared to the full disk, do dump/restore will work pretty fast.