professional developers need to work at multiple SQL queries or worksheets, or packages when design, debug, trace, etc.
To help to organize the multiple worksheets better, instead of clicking on the left and right arrow at the end of the single bar, putting the tabs or tab heads into groups, and allow each group to be in a row, and even better allow each row has its own color.
All these have been available in Netbeans IDE for long time, and it is a low hanging sweet fruit to pick up and make SQL developer much more user friendly and more efficient for big projects which involves multiple PL/SQL packages, procedures, functions, triggers, etc.
Thank you very much.