I don't know if anyone has tried this, but I attached a straplock to the arm on my ns stick. I found a small nut and bolt and lockwasher that fit
through the hole on the strap button. I put it in the slot on the arm with the button facing forward. When your wearing the stick, having the button in the front tends to make the neck and body lean slightly forward
giving a better view of the neck. I found that before I was slightly lifting my right leg pushing against the body to lean the neck more forward for better viewing. That can get a little tiring after a while. I just put it on today, so I'll try it for a while to see how it works out. Has anyone else tried this? The straplocks i'm using are proline g series.

Update: Turned the straplock on the arm around so its facing toward the back now. When facing the front, my left hand was rubbing on the high string and it was a little harder to reach the low b. Works great now. Its just like when you hang the strap without a straplock.

When I owned an NS I was very concerned about not having a strap lock on the ARM but i used the instrument exclusively gigging every weekend for a year with no arm strap lock and never had an issue. I agree however that a strap lock IMO is always a good idea.