Unity Trees leaf resolution with billboard iOS

I recently purchased the OnQ cartoon nature pack, and it includes some great looking unity trees. The trouble is, when you build to you iOS device, if the leaves are in billboard mode they shrink down to almost nothing. The odd thing is you can use cross/tricross/plane geometry modes, and the leaves look just like they do in the editor.

Is there anyway to fix this and have billboard leaves on iOS?

Thanks for any advice!