"Data Type Imports" in "Imports" process property doesn't support list of data types:
There is also no help with custom types.

• For example if a Data Object is created in project with FQN (full qualified name) some.package.SomeType, it is not possible to select this type in Imports. A user has to type it manually.

It was possible to do that in legacy designer:

Acceptance criteria

It will be possible to select all available FQNs (from project, where the process is placed) without needing to input plain String.
Drop down search box can be used for this for example.