The H9000 uses the same algorithm as the SP2016 Reverb plug-in, which is the latest version of the algorithm. The hardware Reverb 2016 is similar, but it's an older version of the algorithm.
This is interesting. So for all intents and purposes, using the plugin instead of the H9000 is essentially the same, aside from shifting resources off the host CPU.
You are correct. There is the difference between using a plug-in vs using an external piece of hardware, the H9000's converters, what digital audio mode you are using, gain staging in the H9000, etc. But essentially it is the same since you are using the same algorithm.