Turn around on the centre, as par my example is 3 cm ....., radius is 2cm
Wheeling on a corner would involve moving on the 4cm radius circle
No, turning around (180 deg.) in YOUR example is 2*pi*2cm/2 which is surely not 3cm but 6,28cm.
To be more precise the radius is not 2cm but 2,24cm because it is the half of the diagonal, what multiplied by 3,14 is just 7,0cm!
Very, very long distance as for just turning around in my opinion. That is why I am still trying to discuss it and try to show that it is against the initial idea of the rules.
In my opinion the right distance is the lenght of the diagonal of the stand which is the distance EFFECTIVELY covered by the stand's corner i.e. ~4,5cm. Lex, if you be so kind to take a closer look at it, then we can discuss further. Do we need diagram?