Matter rollershutter definition

HI there,

because of the problems with the Alexa Skill not receiving values from openHAB, i followed the suggestion and started migrating to the Matter binding.
Switches and sensors were no problem and work fine.

But now i tried to integrate my rollershutters.
In homekit you need a group and multiple items to represent a rollershutter.
You need atleast CurrentPosition and TargetPosition.
These are not available in matter or atleast not documented.

I played around with multiple items, e.g. the group that i also use for homekit.
The item is shown as not responsive in the Alexa app.

Any ideas?

kind regards
Michael