Hey @Termius, apologize for the delay.
+1 from me for auto-connect u2f-devices to termius-app and termius-beta. Can other @reviewers please vote?
Regarding serial-port and raw-usb, I believe serial-port should be enough for your use case. Have you explored the Hotplug support? What specifics errors/denials are you getting that you are also requesting raw-usb auto-connect?
Thanks!