Unsolved SplitView - handle custom MouseArea

[Matthaus]

Hey Qt devs,
I am facing a challenge with customizing a SplitView handle. Visually it requires a width of 2 to display a thin line between two containers. The problem is that the MouseArea where the user is clicking to drag has also a with by 2, which is of course too small. I tried multiple approaches like adding a MouseArea with a width of 12 as a child and playing around with the z-parameter but nothing worked.
Is there a way to attach a custom MouseArea with a greater width than the handle itself?

Greetings
Matthäus