Creating a System Image Restore Point is a process that takes several hours and gigabits of hard drive space, while creating a (regular) restore point, which only saves the drivers and a few other system settings, takes just a few minutes, so I wouldn't be so sure Windows will create an extra System Image Restore Point before restoring another one. At least I wouldn't take the risk even if I saw Microsoft documentation say so (I did not).
I'm not sure what you refer to by Lenovo's fix resulting in the problem and obviously the solution is more important than who to blame, but just to recap how things went (all this is already said in my original post): First Microsoft's operating system refused to recognize my face from the video the camera was nicely giving to it, and when I did according to instructions given in Microsoft forum, the entire Microsoft feature stopped even starting while every other application continued and still continues to co-operate with the camera just nicely. Only then I contacted Lenovo and since their "fix" was unacceptable, I did not do it but came to this forum.
We are talking a lot about drivers and other stuff that in my mind is totally irrelevant in this problem, because every other application still continues to interact with the camera perfectly even though we have done our best to break also that by installing several random and more or less suspicious driver versions. It's the Windows Hello Face that has the problem.