Basic notification, as defined in ONVIF spec, only applies IP camera and NVR in the same network segment. The notification will not be able to be transmitted if the camera is on the Internet and NVR is inside an NAT. This call-back style requirement also potentially requires the user to turn off any firewall mechanism that might exist, even in production stage.
The limitation & requirements introduced by basic notification will likely to cause extreme confusion when problems arise in the field, and it's very difficult to sort out the cause of problem in short time or in an obvious way. In practical sense, using basic notification will significantly increase the support cost to all roles of IP video deployment, including system integrators, VMS software developers, and IP camera manufacturers. In contrast, pull-point style notification does not have these problems.
Therefore, we believe that using real-time pull-point style notification is the most appropriate & easy way for deployment of ONVIF event notification, which spares the users the effort from (1) having more IT/network knowledge (2) knowing the exact IP locations of camera and the NVR, in order to use event notification.
Furthermore, requiring users to turning firewall off even in production environment is controversy, we will not recommend users to do that.
For all the reasons stated above, we don't plan to add basic notification to Genius Vision NVR.