I have Smush installed, then installed WPMU Dashboard and logged in.
After I saw "Smush Pro" in navigation but "Smush" in plugins.
When I needed support with Smush Pro for the given website, I can't choose Smush Pro (nor Smush) from my Plugins list. I had to install Smush Pro (which asked me to re-smush all my images I'd just smashed them by Smush).
Some Smush -> Smush Pro upgrade would be nice. Eg. Defender prompts to install Defender Pro after WPMU Dashboard is activated.
But no big deal, it is just a bit confusing at first.