In the line to which the visualization is connected, a large part or even all group telegrams are passed through (otherwise the visualization would not work). If these group telegrams are not confirmed, they would be repeated three times and thus generate a potentially significant bus load.
Since the (link layer) confirmation immediately follows the data telegram, it cannot be generated on the PC, but must be sent independently by the interface module. Elvis operates the interface in an operating mode in which it automatically confirms all group telegrams (no matter which group address).
This statement applies to all RS.232 and USB interfaces certified by EIBA or KNX.