Actually I had spoken to Doug Whalen about producing one about a year ago. I even did the measurements.
Basic outcome was this:
The MINI linkage is pretty sloppy and if you take the full range of motion into account then you end up with little thin fingers, approx, 5-7mm, between gates and big, 20mm or so, gates.
Now TBH I did this with my aftermarket shift arm(ProMIni) which is thicker than the OEM arm. But if you have ever looked at the OEM arm under the boot you would realize just how f'kn ugly it is and you would never want to expose it.