f-stop and wide angle

[Mariozi]

Thank you for your explanation, like most things that seem simple at first, further invstigation reveals increasing complexity, like the rabbit hole in Alice in Wonderland, you can drop into a strange world. N

Yeah, it's something like a grey area. You were not wrong.
You can interpret the "m" as being the factor where DoF comes into play for the geometric DoF, but when you do the "crop" to compare to the picture taken at another Focus Length, the things evens out at the Print DoF and you have effectively almost the same image (there could be some IQ differences in the different Focus Length settings like differences in distortion and resolution for example).