Prior to purchasing (can't wait!) the Cort Space 4 Thomann music shop have today written to me to confirm the following:
You can use any standard roundwound strings on this bass, and the clamp on the headstock allows you to use standard bass strings.
With flatwound strings, the winding can break due to the pressure of the grub screw (which secures the string to the headstock).
Therefore, we cannot recommend these clamp screws.
This is due to the design of flatwound strings.
That's disappointing news but if anyone on here has been successful with using flats on this bass I'd love to know.