I think ncmncm is a total scrub, but I will say two things:
First, both adding an ampersand after auto when you shouldn't have and not adding it when you should have can lead to logic errors of different kinds. Sometimes either one is fine, sometimes you have to use the correct one.
Second, auto * vs auto by itself has no effect on the generated code, but it can lead to a more robust source. Imagine that you get a pointer from some function and you perform some operations with it, assuming it actually is a pointer in a way that would be invalid if it wasn't. If the function signature later changes to return a pointer-like object, you'd want the compiler to give you an error to know to fix that code. In other words, you should use auto if you really don't care at all if the value is a pointer or not, and you should use auto * if you're assuming it's a pointer.
First, both adding an ampersand after auto when you shouldn't have and not adding it when you should have can lead to logic errors of different kinds. Sometimes either one is fine, sometimes you have to use the correct one.
Second, auto * vs auto by itself has no effect on the generated code, but it can lead to a more robust source. Imagine that you get a pointer from some function and you perform some operations with it, assuming it actually is a pointer in a way that would be invalid if it wasn't. If the function signature later changes to return a pointer-like object, you'd want the compiler to give you an error to know to fix that code. In other words, you should use auto if you really don't care at all if the value is a pointer or not, and you should use auto * if you're assuming it's a pointer.