There's unexpected news:

While the latest version works well using wlan as it seems, using ssh over usb network makes it buggy and even worse unusable. The latter is due to a seeming bug in sshd regarding "ForceCommand". Login hangs.

This means the wifi pm feature has to be rewritten using a different approach than using "ForceCommand" in sshd config in order to make the widget compatible with usb connections.

After a search I found out how to count just wlan connections without gettings triggers from the users logging in. Apparently this is my friend now: "netstat -ant | grep :22.*ESTABLISHED", because he lets me count ips.

In case you want to install the widget as it is and use ssh over usb you have to comment out "ForceCommand" in /etc/ssh/sshd_config. As a result the wifi pm feature can only be started manually using the wifi pm button. It will then be active as long as the last user logs out, including usb connections. Therefore a fix is attached (if it works as expected). After removing the suffix, making it executable and copying it into the folder

"/usr/lib/openssh"

wifi pm should switch back to "on" when the last wlan connection is closed (with a max. delay of 40 sec).