Can node in groups auto adjust on div assigned space

we have two groups which are having different nodes but they are not auto adjusting to all the space, div has lots of space but most of space is useless.

I tried to set the stretch: go.GraphObject.Fill for group, panel ,shape but it does not work. PFA

myDiagram.groupTemplate =
(go.Group, "Auto", { name: "groupSS", layout: (go.TreeLayout,
{
breadthLimit: 1500,
layerSpacing: 100,
nodeSpacing: 100,
alternateLayerSpacing: 100,
alternateNodeSpacing: 100,
rowIndent: 100,
angle: 90,
arrangement: go.TreeLayout.ArrangementVertical,
sorting: go.TreeLayout.SortingReverse
}
),
alignment: go.Spot.TopCenter,
avoidable: false,
stretch: go.GraphObject.Fill
},

If i increase the size of layer and node spacing then all size of all nodes inside group getting decreased .

The size of any Node (including any Group) is independent of the size of the viewport. What would want happen as the user zooms in or out? Or if they scroll to the left or right?