Are you running docker on the PVE host? Or within a LXC container or VM?
Note that running docker on the PVE host is not recommended as this can cause networking problems for both docker and the host+guests
If you are running docker in a VM as is recommended then pass thru the USB drive to that VM, it will act as if it was plugged directly into the VM.
Besides lots of other cool stuff it can do (including monitoring for a lot of your self hosted stuff), HomeAssistsnt has the Feedreader integration, which lets you poll RSS feeds. You can then create automations to send notifications to you through the HomeAssistsnt companion app.
Feedreader defaults to polling once per hour, but you can change this in the configuration.