My workaround is this:
In the Startup Skript I added the following code
The result is only a text which displays the value ( but it seems like this text has the correct formatting and scaling factor).
I still have no idea how to connect this Value with the "value" from the KPI_Tile.
One of the great features and reason for the use of the KPI_Tile was the simple selection of a specific data cell to display which is now untenable.
Regards
Steffen