@eskimo : Did you get anywhere with your research? I have just run into this issue too.

Thanks Kevin, I have created FB14191591

Hi Kevin, As you say neither of these is suitable since the volume is expected to be mounted and in use. I think this is still possible with a kext though? I will file an enhancement request since a DriverKit solution would also work on iOS / iPadOS which relates to the other question you answered for me the other day.

Thanks Kevin, I have created FB14275983

It is a data processing device for media files. It is designed to be used on location or on set for video productions. In these locations there may or may not be internet. Examples: iPad Pro, USB ethernet directly connected Macbook, using TBT4 networking iPhone, using Wi-Fi network served from our device Networking allows control of the device and serving of files over SMB which can be mounted on the apple device

Yeah exactly that, a task finishes on the device, which we want to tell the user about, even if the application is off-screen at the time, so we want them in the Notification Center.

Thanks for the link to the Local Push extension stuff. I had looked at that before and forgotten what it was called. It still doesn't solve USB / Thunderbolt / Wired networking as there is no way to specify those networks so might not be the right direction for us.

I have filed a feature request FB16077739 My suggestion is that Local push could match on a DNS-SD advertisment provided by the device. That way it could work on all types of local network.