Hi @Ext 45211
For disabling call related feature: https://github.com/ringcentral/ringcentral-embeddable/blob/master/docs/disable-features.md#disable-call-related-features

And currently it doesn't support to hide Voicemail, Fax, and All tabs. And feel free to create issue for feature request here https://github.com/ringcentral/ringcentral-embeddable/issues
For getting Web Phone Unavailable, you can change default calling mode to others https://github.com/ringcentral/ringcentral-embeddable/blob/master/docs/interact-with-calling-settings.md
For permission error message, it should be hidden when you disable call related message.
For click to sms, can you show how you implement it? It should work and you can try the demo in https://ringcentral.github.io/ringcentral-embeddable/ Or you can use the api to open the widget https://github.com/ringcentral/ringcentral-embeddable/blob/master/docs/control-widget.md#minimizehideremove-the-widget

@Embbnux Ji Thank you for the response. I will try them. We have also a feature to display message templates dropdown on send sms page where user can select a message template which wil be prepopulated. We need to write customization for this. In this case, do you think we need to take this project and customize on own or start with widgets. Can you please provide direction in which we need to design architecture. At this point I think start with embeddable and customize may be little faster but not sure if thats the right direction. Please provider your inputs.

You can implement this feature out of the widget with click to dial API. https://github.com/ringcentral/ringcentral-embeddable/blob/master/docs/control-widget.md#go-to-sms-page-with-prefilled-text
But the template select UI will be out of the widget. If you want to dropdown to show in the SMS page, you need to update source code (react component).