Hi,
one finger zoom is one of the best things in Panels on iPhones in my opinion. A small thing that bothers me with it is that when you use it with your thumb at the most comfortable position (like 1/4 of the screen height from the bottom) and move the page up, the bottom of the page is covered by your finger because you cannot move the page further up.
If you do the same thing at the top (1/4 from the top) you can move the page away from under your finger, also when you place your finger way at the bottom of the screen but then you can‘t move it down enough.
So to be able to scroll about the whole page without having to re-set your finger down would really improve the experience with it I believe.