I have used the Nestle several times in the past few months, and mine do not have a yogurt consistency, but that of a thick paste, like tomato paste. What I mean is that, unlike yogurt, which softens as you stir it, I have not had that happen with the Nestle brand. Maybe what I bought was older stock. I am sure that it can be thickened further, on the stove top over low heat.
I agree with you about not boiling the can of sweetened milk. It is not something I would do, either.
I thought someone had posted information on making caramel from sweetened milk, by microwaving or stove top, but I cannot find info on it in my desktop archives. Sorry, I thought I had saved the info.
Does anyone recall a threadlike this?