I never got a response on this. Can Obihai answer?
It seems to me that one of these check boxes may have something to do with times when the network is down [or the box is not registered] but I haven't been able to verify. I discovered by trial and error that if the network is down and I pick up the phone and dial, there is a delay of about 40 seconds before I get a response from the Obi. It seems to me that I should get either an error message or at least fast busy since the Obi knows the network is down even before I dial. I don't have a problem with it still giving me dial tone and letting me dial since the call may be routed to the PSTN anyway. But after I dial it shouldn't take 40 seconds for the machine to let me know what is going on.
Related question: Most of these ATA's have a setting that says "Allowed to call if not registered? y/n" which some ITSP's require. I don't see this anywhere in the Obi 110.