Currently in SMAX the grid shown as M:M link displays predefined columns (chosen by the system).
User can change using the proper button.
But if user logs out and logins again into SMAX and enter the same page as before, the columns are again the predefined ones.
It looks like SMAX doesn't remember the user's choise.
In addition, it should be very useful to allow user to choose the columns to be shown in the M:M grid just at the creation (in Studio).