Created attachment 94520 [details]
With and without feature enabled
It would be very convenient for LibreOffice to have the ability to toggle automatically resizing the chart around the legend. It's very tedious for the user to have to resize and move the chart around the legend, so it should be enabled by default.
This feature could be disabled by a check box in Chart->Edit->Format Legend->Position.
The feature could also improve interoperability with Microsoft Office files, since they have the ability to toggle this setting.
Created attachment 94521 [details]
Chart showing showing feature check/unchecked
This .xlsx chart does not open properly in LO 4.2 or 4.3. Hopefully adding this feature would help.
Looks like a reasonable feature request to me.