I guess the issue is not the brand of wrist strap, but the strength of the strap lugs in handing the weight of the camera, if only one is used rather than two, as in using a neck strap.
It has been claimed that later Leica models have revised manufacturing methods for attaching the strap lug to the camera body, making them less sturdy than the earlier models. However, you are not meant to grab the strap and use the camera for hammer-throwing practice to start with, so it should not be really an issue if used properly.
As I manufacture my own brand of wrist straps, and have been using them for extended periods, I never find that it puts undue demand on the strap lugs at all.