Most home computers completely ignore the index hole, so you could definitely have used hard sector floppies on them. The C64, Apple II and Atari computers for sure - and probably more. These machines used single sided drives, and you could make "flippy" disks by punching an extra write protect notch in the other side of the disk, and turning it over. Since the machine ignores the index hole, it doesn't matter than it's now in the wrong place.
I know that the Tandy Color Computer actually does use the index pulse, because to make flippy disks for that, you have to notch the edge AND punch an index hole through both sides of the jacket without damaging the media.
I have a Heathkit H8, which uses hard sector floppies. I'd be very interested in seeing how you built your disk punch, Dwight. Do you have any pictures of it?
-Ian