The built in integration uses a newer API for the bond hub which eliminate the polling. You can have both integrations running at the same time, so you could test switching one rule over to the new devices to see how it works.
Not sure why it wont find it. Is there no way you can update the firmware on your bond hub? The system integration might also rely on mDNS or some other discovery method to find it, may be getting blocked in your LAN or something.
If you need to stick with the user integration and want it to work you are going to have to do some debugging for it yourself.
