TreeView / styleData is too restrictive

Suppose, I use TreeView and want to

1. display some decoration left to text,
2. have custom background colour
3. have custom font of my text
4. and so on...

How can I achieve this? Seems it's impossible.

So, I propose to expose model in TreeViewItemDelegateLoader.qml to user. For example, if you add something like

+        readonly property var modelPrivate: model

to TreeViewItemDelegateLoader.qml then everyone could use it in following way:

color: styleData.modelPrivate["BackgroundRole"]
text : styleData.modelPrivate["DisplayRole"]
font : styleData.modelPrivate["FontRole"]

(Actually it is exactly what I have already done locally, and it is works perfectly)

What do you think about this?