I think to have solved my issue (zenographic vs zeonocentric latitudes) simply adding in my usual zenographic maps a graphic scale with the zenocentric latitudes conversion. 
Of course there is  not a linear relationship between the two systems. What do you think? 
In my opinion we can easly compare my maps and the  (zenocentric) ones produced by the Juno's team, without plotting two different maps.


[Marco Vedovato :Predazzo Italy:Long 11d36' Lat 46d19']