The response from Tomtom support is that my request to import POI files has been forwarded to the appropriate team but that adding new features can take a long time. I have complained that this feature exists in previous models and is something a lot of users would need and can't understand why they have decided to omit it in the Expert model.
@Orni, assuming that it may be a long time before Tomtom fix this, or maybe never, does the NAV5 patch work for the GO Truck Expert and would it enable me to copy my personal POI files to the device.