Just to update on the reported issue. @alvin1118 of Vinshine Audio provided instructions to update Amanero USB firmware. That seems to resolve the issue with jumping tracks (similar issue as reported by @bt304, thanks) but I have not played long enough to conclude yet.
Regarding Sony HAP-Z1ES showing "An unsupported USB device has been connected" error message, if I turned on Terminator first and select USB input, then turn on Sony HAP, then there is no error at all. After that, with both devices already on, if I switch Terminator to other input (Amanero shuts down) and then back to USB (Amanero powers up), there error "An unsupported USB device has been connected" still shows up.
Regarding Sony HAP-Z1ES showing "An unsupported USB device has been connected" error message, if I turned on Terminator first and select USB input, then turn on Sony HAP, then there is no error at all. After that, with both devices already on, if I switch Terminator to other input (Amanero shuts down) and then back to USB (Amanero powers up), there error "An unsupported USB device has been connected" still shows up.