My melody has an eight note pick-up bar, this I can do. If my time signature is 2/4 then my last measure should be incomplete and only have the value of 3 eight notes. Is there a way to do that without creating a 3/8 measure at the end and hiding the measure symbol?
No, you have to add a 3/8 time signature and then hide it (from the properties panel).
edit: ignore this and go with Rob’s suggestion!
You don’t need to create and hide a time signature.
Open the “bars” panel on the right hand side of the screen, and insert a final barline where you want it in the middle of a bar.
If that leaves a short bar after the final barline, do Trim Flow in the Write menu.