The Vaadin Collaboration Engine for real-time collaboration only has example for Vaadin Flow. Can you use it with Vaadin Fusion?
There's currently no support for using Collaboration Engine directly from Fusion, but there are two ways of getting partial benefits already today. These are just theoretical ideas, I haven't tested either of them in practice.
The first approach is to use Flow to configure and control the components that should have collaborative features, and then use WebComponentExporter to make them available as web component that can be used from Fusion. This might be quite practical for the avatar group and the upcoming discussion features, but not so much for form binding.
The second approach is to use the low-level data synchronization Java APIs from Collaboration Engine and expose those through Fusion endpoints (with a separate push channel). You could then use that data synchronization layer to implement your own component integrations.