Given that other companies provide real, not mystery sleep SPO2 charts,
yes, that's allowed. Keep in mind that any firm may have disclaimers and
limitations, and may need Fed approval for certain things.
As to on demand or real time, here are some issues;
1. Finger clip works best because it can shine lights through finger.
2. A number of brands do on demand, maybe every x seconds or minutes.
3. One issue; because it uses reflected light sources, it's harder. On the
brand I use, it needs your wrist and hand to be reasonably warm - in my
case, my hands are always cold unless I do something I do something first.
But if the wrist and hand in question are warm enough, it works well.
4. I don't know if any current watch can get good results when you're
walking. But the tech keeps improving.
5. I'm still glad I got something that works.
