Oh I am in the same boat where I live! 30t front with a 42t granny!
Stoked to see the top guide works with a 30t front ring! I've been searching the interwebz for someone with the new BCD running a 30t and a top guide!
Really well. Super playfull! Smashing corners, jumping everything, easy to manual! It handles like a nimble trail bike until you open it up and than it charges like the best of them. Very impressed so far.
Gear range is 30 x 11-42. Need that granny on the shore!