I quite agree. (It an unsupported "feature")

If you don't discourage it and it does not work,
then you will likely get calls. (That you must turn away.)
I hope the tests are going to prepare VOIPo. I will abide
by any policy VOIPo will require as a permanent customer.
As Beta, you want us to push the limits

I thought you might push GS and Soft Phone on one line?
Not sure what your Soft Phone strategy is now?
Just another BYOD-like single device offering?