Don't change size only by mouse-wheel:
I find it annoying when the size is changing when scrolling up / down with the mouse wheel while the cursor is hovering over the chart.
In general I think it's a nice idea to change the size with the mouse-wheel, but it should only happen when I additionally press Shift- or CTRL-key - and the screen shouldn't be scrolled at the same time.
Remember the size:
It would be great, if the size I used would be remembered between sessions.
Show the last data by default:
Right now the chart shows the first data (scroll bar at the left end), it would be great if the last data would be showed by default (scroll bar at the right end).
This is unfortunately too complex to touch now, but it could most likely be corrected for an upcoming release.
Mousewheel scroll/pan will be inactivated for the next build.