Yes I did try connecting the USB drive directly to the OTG cable (no USB 3.0 Hub present), and again, whilst I can see the USB drive from Windows 8.1, I am unable to see it from the Boot Manager menu.
My purpose is to prepare for upgrade to and potential fallback from Windows 10, so I don't know whether Windows 10 would be able to see it, though if Windows 8.1 can, I would expect that Windows 10 could too.
This is the OTG cable that I am using: http://www.amazon.co.uk/gp/product/B004 ... ge_o02_s00
This is the USB 3.0 Hub that I am using: http://www.amazon.co.uk/Superspeed-Bus- ... +usb+3+hub
I have the micro USB connector of the OTG cable connected to the Linx 8.
I have the black plug of the OTG cable plugged directly into the USB 3.0 Hub's USB IN socket (i.e. USB Hub is therefore operating in bus-powered mode).
I have a USB mouse, keyboard and 8 Gb USB drive plugged into the USB 3.0 Hub's USB OUT sockets.
I have the red plug of the OTG cable plugged into a USB wall plug charger capable of delivering 2 amps, and is therefore powering both the USB 3.0 Hub, it's connected devices, and the Linx 8 tablet. Under Win 8.1, the taskbar power icon indicates that the Linx 8 is plugged in and is charging. Mouse, keyboard and USB drive all work fine from Win 8.1's point of view. So it does not seem that there is any USB powering problem.
It's just the UEFI/Bios level where I have the problem. It does not see a the bootable USB Recovery drive I created at the Win 8.1. level. Same problem encountered with two different USB drives. I don't have a USB 2.0 Hub to try, but understand that USB 3.0 Hubs are fully backwards compatible with USB 2.0 devices.