hm...
i never thought about changing the size of moving with shift + arrow key. but in your particular task it would be quite usefull i agree.
unfortunately i have no settings dialogue yet, where i could add it in a minute.
let me think about this
And is there a keyboard shortcut for "Duplicate" a matrix?
there's a duplicate button on the modifier shelf but you may have noticed that. what shortcut would be good and easy to remember? CTRL-D is reserved for deselect... suggestions?
i like the image you posted

hope to see more in the gallery soon ^^
i would like to move this post to feature requests if you don't mind