Not sure what you mean by the last sentence here, can you elaborate? What I'm saying is that the fact that this strange mathematical result happens to give correct results in a physical experiment must be a pointer to something.
There are stuff like this https://en.wikipedia.org/wiki/1_%2B_2_%2B_3_%2B_4_%2B_%C2%B7..., but writing 1+2+3+... = -1/12 is purely formal and pretending to deduce it from physics is silly because you are not performing any sum at all.