Suspension and LSD are very much up to preference, for the very few tunes I have shared I have heard they are either perfectly balanced or too understeery.
To me of course they are a bit of both.
I dont have any tune for either Mazda Gr.4 car, but as far as I remember they are quite fine.
I wouldnt use the Mazda 3 as it is FF and the Atenza is or was considered the OP choice for the Gr.4 cars.