Windows server + client in a VirtualBox guest: per-port power cycle of the 4-Port USB 3 Hub while VirtualBox owns the device

Hi, I bought the VirtualHere 4-Port USB 3 Hub and would like to check a setup before it arrives.

Setup

• Host: Windows 11 PC running VirtualHere USB Server for Windows, with the hub plugged into it.
• Guest: a Windows 10 virtual machine running in VirtualBox 6.1.38 on that same Windows 11 host (USB 3.0/xHCI controller, NAT networking).
• Device on a hub port: a USB device that is powered only from its USB port, so switching the port power off/on fully reboots it. A VirtualBox USB filter is set up for it, so whenever it connects it is passed to the guest.

Use case
My use is a bit different from the usual remote-server setup (e.g. a Raspberry Pi server reached over the internet). I want to use per-port power switching as a software “unplug and plug back in” to recover a USB device that has hung. A person would normally do this by pulling and reconnecting the cable. Because the device is already registered in the VM’s USB filter, after the port is power-cycled the device should start up again and be re-attached to the guest automatically.

Goal
From a script inside the guest, power-cycle the hub port the device is on, e.g.
vhui64.exe -t "MANUAL HUB ADD,<host-ip>:7575" then vhui64.exe -t "CUSTOM EVENT,<address>,power_cycle_port".

Automation (no person at the PC)
This will run as unattended automation. An AI agent running inside the VM watches the device. When the device has not responded for a certain time and the agent decides it needs a restart, it sends the power-cycle command from the VirtualHere Client in the VM to the server on the host. Nobody is there to click a Windows UAC (administrator) prompt, so I need to know whether any step of this requires administrator rights. That covers sending the command from the client, the server carrying it out, and the device reconnecting afterwards.

Questions

1. Does the Windows server take over (install its driver for) every USB device on the host, or only a device when a client uses it? Is there a config.ini key to exclude a device (by VID/PID) from sharing, and does an excluded device’s port still accept power control?
2. Can CUSTOM EVENT … power_cycle_port be sent for a port whose device is currently captured by VirtualBox (VBoxUSB), i.e. not shared by VirtualHere? If not, is there an address for the hub port itself rather than the device?
3. Is a client inside a VirtualBox guest on the same host (NAT, connecting to the host’s server over TCP 7575) supported for this? Does CUSTOM EVENT (or anything else in this flow) need admin rights / a UAC prompt on the client side or on the server side? If the server runs as a Windows service, is that enough?
4. Forum comments mention Windows re-enabling a port right after it is switched off. Is unticking “Allow the computer to turn off this device to save power” for both the USB 3 and USB 2 parts of the hub the recommended fix?
5. After a reboot, the device reconnects about 1.5 s into its boot. Through VirtualBox USB passthrough, that early connection never carries data until the device is re-attached later. Would sharing the device to the guest through VirtualHere (instead of VirtualBox passthrough) handle such a device, e.g. with auto-use?

Thanks!
David Hyun Gil Kim