The magnification factor of any lens regardless of dimensions is the magnification factor of that specific lens design.
The sensor does not come into it, the size of the projected image at the film plane is what it is.
There is no point comparing apples with elevators. It's a silly rabbit hole to go down.
If you can show me a full frame EF camera that can be adapted for m43 then I'll maybe consider your point... until then....
And beyond that point, as I've already said... even if you were to allow for sensor crop etc.. the sensor designs, pixel pitch, microlens designs etc are so different that there really is no useful comparison other than to see who can pee the highest under lab conditions (spolier, it's always going to be FF)
If it works for you enjoy it. All the best.
OK, since you won't do it, I'll do it for you.
Q: How wide (in mm) is the physical subject filling the view in landscape orientation for a M43 lens at its claimed 0.24x max magnification and a M43 sensor?
A: A M43 sensor is 18mm wide. Since we know a 1:1 (1x) magnification is a true "macro", and a true macro by definition will place the same size subject width onto the sensor width(18mm), then the subject width would be 18mm. Now a .24x magnification is less magnification, so the image on the sensor would correspond to a bigger subject width, so subject width = sensor width / magnification. So the subject width = 18mm / 0.24 = 75mm
Q: How wide (in mm) is the physical subject filling the view in landscape orientation for a FF lens at its claimed 0.24x max magnification and a FF sensor?
A: The FF sensor is 36mm wide, so subject width = 36mm / 0.24 = 150mm
So the picture taken with the M43 setup is of an object half as big as the picture taken with the FF setup.
Now if you want to claim these 2 pictures are the same, then you go ahead. But show the two pictures to ordinary people and ask them if they're the same. They'll say "No" since the subject content of each is different. So they're not equivalent.
When I talk about one system taking an "equivalent" picture as a different system, I mean that the content of the picture in one is the same as the content in the other. Otherwise there is no use in calling any two pictures "equivalent" at all. A single photo printed to two sizes of 4x6" and 8x12" will be "equivalent" photos to me. If you ask an ordinary person if they are a photo of the same thing, they will say "Yes". That's why they're equivalent.
Ok, if you want to define "equivalent" some other way, then go ahead.