My understanding is that since IP cameras are basically mini Linux servers, they should be able to support Profile G just like any 'normal' NVR running on a traditional box or PC. That said, I reached out to the ONVIF technical committee for comment.
Btw, I have not heard any manufacturer announce official (or planned support) for Profile G. If anyone knows of such support, please share.
Profile G is going to cover edge storage, yes. As ONVIF told me in the past (though without much detail), the storage framework is to be applied to any storage location, so it applies to edge storage, network attached storage, or server-based storage.
Bosch hasn't announced official support, but their firmware release notes include addition of "beta features" for Profile G in 5.60.
Here's the answer on edge recording directly from a contact at ONVIF:
IP Camera edge storage is one of the two main use-cases covered by Profile G, the second one being NVRs. A Profile G IP Camera with edge storage will allow a client to query a list of recordings in order to configure, enable or disable them as well as build a timeline and request media streams for playback. It a bit different than a camera acting as a VMS as the Profile specification was written from the start to address IP camera edge storage use-cases.
So yes, it will cover SD card recording. It's not intended to be a VMS replacement (like Axis Camera Companion), but it will point the VMS to the SD slot as a storage location.
However, wouldn't I be able to build my "ONVIF Camera Companion" where I add in playback / search features using ONVIG G to connect edge storage on cameras supporting this?
Thanks for the feedback guys. I wasn't so much interested in whether a camera can act as an ONVIF conformant VMS on its own but if a 3rd party VMS is Profile G Compliant and a Camera is Profile G compliant then will the VMS be able to store to and retrieve data from the camera's SD card "out-of-the box" (no integration work) as just another storage location. The answer you got from ONVIF indicates the answer to this is yes but it is not entirely clear.