I can't find a spec for its isolation capacitance. They only include the default "isolation voltage", e.g. what the device can withstand without damage. Without isolation capacitance, you don't really know what "isolated" means.
I see they imply a DC/DC converter is used for power isolation. The spec sheets for those modules almost always specify their isolation capacitance, and it's generally not very good (the value is too high), so the effective isolation isn't as good as you'd expect. So if they've started with a module, this thing's actual isolation can't be better than a typical DC/DC module, which ain't all that great.
Disclaimer: I have a USB isolation unit made by Linear Tech, and it does provide some isolation, but nowhere near what any small signal Engineer would consider "isolated". You can definitely tell when it's in the circuit (though it's better than a direct USB connection).
There's still room for improvement in this area, for sure.