Is there a built in solution for this yet? There is a still strong business case for this to exist.
So is there now a way to duplicate a task in a different project within a workspace?
Yes, this can be done. Highlight the task and click the menu option with three dots for more options and select “Add to another project”. You can also select multiple tasks by holding down CTRL as you select tasks then click the option on the little menu that pops up at the bottom of the screen to Edit Project or Section. There you can the whole list of tasks to a different project and specify the specific section you want to add it to in the project.