Hi @brainbomb, thanks for the post.
I have not noticed any differences in functionality when denying those permissions with the sample application.
- Is this expected behavior if the user chooses Deny?
No, this is not expected behavior. Can you please try updating to the latest version of the SDK?
- If so, could the SDK be updated so that meetings are still possible after the user chooses Deny as is possible in the official client?
Meetings should still function normally regardless of your selection.
- Since the dialog doesn’t present a great experience for first time users of our app, could the SDK be updated to allow for opting out of requiring keychain access entirely?
This seems reasonable to me. I will submit a feature request to allow these requests to be hidden. There may be some aspects of the SDK (e.g. “remember me” option when logging in) that would not function without this, but as long as it is configurable to hide these, that should not pose any major issues. I will let you know as soon as we have any additional information on this feature request.
In the meantime, please don’t hesitate to reach out if you run into any other issues or have additional questions. 
Thanks!