Following the paint position in another tool?

I'd like to automate something in fusion and I've no idea how or even if it's possible. What I'd like to do is somehow gain access to the current paint position in a MaskPaint tool (which has been set to write-on so that the mask appears over time) and set the center position of a transform tool to that value. That way, a piece of media that the transform tool is connected to can automatically move to follow the "tip" of the MaskPaint tool as it progresses.

Is this possible? Thanks for any pointers as to how this is accomplished in Fusion.

Normally I would advice you to use a polyline for the maskpaint-tool and then connect the path of a merge or a transform to that polyline and connect the 'displacement value' to the the 'write-on end'
This *almost* works, except that for some reason the way the spline is interpolated by the 'write-on end' and the 'displacement value' is different. Start and end time will be the same, but they will not match up exactly. I am still not sure why.

A way to work around this, is to make a duplicate of your maskpaint tool and make the write-on start follow the already animated end with an expression or offset modifier. This way you can make the mask a moving 'dot'. Track this dot and you'll get the path of the current paint position, then you can use this info to drive the center of your transform tool.

Thanks Sander, I'll give that a shot.