Hi Eric,
Sorry for the inconvenience caused.
We have checked with you query “that following the sample in docs, cannot bind the radio button to view model” and unable to reproduce the issue from our end. For your convenience, we have created a sample as per in the documentation and attached in the below link. Please check it.
If your requirement is two-way-binding, then we inform you that there is no support for two-way-binding for radio button. Also, we will consider this as a feature and will be included in our next release.
If we misunderstood your query, then please get back to us with more details along with an issue reproducing sample (if possible) so that we can provide the exact solution as per your requirement.
Regards,
Prem Kumar. M