What inspired this wish list request? I use the tree map as a the base graph to report out a dashboard of summary statistics for multiple areas in my plant. The current squarify option leaves some "boxes" almost useless.
What is the improvement you would like to see? I'd like to see a "forced square" option in the Layout drop down menu that would make the boxes all the same size, which could mean that there are blank boxes if there are not enough categories to fit a even row/column matrix. Ideally every box would look like chem mill stacked or heat query stacked. You can see on dry times stacked that there is one long and skinny box that is hard to see.
Why is this idea important? Dashboards are becoming key tools for conveying operational status quickly so charts that are easy to see all the elements are vital. This is also critical as we move to JMP live as dashboard style graphics are a main reason for the move.