This obviated the need to copy a filesystem to a new disk's swap space and then use that to really install the system.
Thanks for the reminder. I don't remember if V7 on the PDP-11 used the swap space (but I don't think so). That said, I fairly sure that by BSD 4.1 the boot loader did, which I think is when that trick was first added to boot phase.
Just checked the archives. V7 had a stand alone program to restore a filesystem image form the tape to the disk that you ran after running the stand alone program to partition and newfs the disk... I think you are right on your timeline. I installed a dozen Sun3 boxes from tape and hated mistyping the file number and having to start over...
Again, it was all about trying to get rid of the special /stand version of things. Funny, history would move on and we come back to that idea with busybox 🤔
Well, busybox is special in many ways, so there's that in common with /stand, but it runs under a full otherwise standard kernel, not as some special mini-exec that provides just enough of the unix APIs to keep the standalone programs happy.
Warner