Have tried SMBIOS iMac 18,3; iMac 18,1; iMac 17,1; iMac 14,2. Same result with all. Have tried adding secondary hex numbers to the first group of "Find" and "Replace" as seen in the PLRPs for 10.14.4. No change. Have tried ACPI "InjectUSB" check box both checked and unchecked. Have tried "Automerge" checked and unchecked. No change. Something or other changes the 15th USB port back & forth between "USBR1" and "SS01" but I cannot determine what does that. Is there some setting in the UEFI BIOS (F22e) that can cut the missing ports loose? I even tried buying PListEdit Pro (for $30) and configuring using that instead of Clover Configurator. No change, and both apps give the same result in the text area of PListEdit Pro anyway. What am I missing? I dumped the DSDT (using F24 in Clover) and it shows HS01-HS14, USR1, USR2, and SS01-SS10. So those SS ports are there, I just can't make them visible in IORegistryExplorer.