I know what you mean but I'm not sure what all can be done about it.
However, one thing you can do to somewhat enlarge the chart is to save just the chart and not all the MT4 screen. Use the right click on your mouse in the charts body and you'll get a list of options...one is to "Save as picture". You then get a choice of pic options including pixels.
As you know when uploading, Babypips only allows a 700 pixel max, but MT4 saves charts with a default of 800 x 600 pixels, so I believe the pic gets distorted by Babypips a bit to pare it down to 700 x ?(relative)

Otherwise I suppose we could save them with 700 x 500? pixels instead.
What limits does FF have? We can always suggest that BP give us at least an extra 100 pixels. I also find black backgrounds harder to see when posted as screenshot...jmo.
Hope that helps
