I have found UltraViewer as a valid replacement for TeamViewer (which has become impossible to use with its timeouts after 5 minutes of use).
UltraViewer is completely free (at the moment) and it seems to works like TeamViewer.
The latest release supports command line switches to pass ID and Password.
Looks like the translation to English still needs some work, based on the website.
I will add this to our todo list. In the meantime you can use a Command Line session to invoke the executable.
For your convenience, On the documentation is not written, but to use CLI switches, the GUI must already be open, so you need to run the executable twice: first time without parameters to open the GUI, the second one with -i:ID_TO_CONNECT -p:PASSWORD
UltraViewer_Desktop.exe -i:ID_TO_CONNECT -p:PASSWORD