T14G3 - internal usb - how to?

[fatal_exception]

So I have T14G3 and T14sG4, both are AMD flavors.
Both have WWAN slot and both have one of the USB ports connected to the MB via a flex cable.

I've bought an M-key -> USB adapter and tested it out on WWAN slot (mouse receiver for anyone wondering) and it worked like a charm... at least until the reboot, where I got the default "this is not on the device whitelist" f-you message.

I know, I can hack bios, I have the programmer and all the stuff that would be needed, but there are some issues:
- bios upgrade is problematic, and it would have to be hacked after every upgrade
- I'm not entirely sure if TPM wouldn't complain and basically would force me to have unencrypted drive, because it would either halt at boot or require me to provide an unlock key every time I start the laptop

It'd be perfect if the power would be delivered to the receiver just after the boot process, getting around the whole protection, but unless there's some simple hack for that, I'd say it sounds way easier than in reality it would be.

So that would leave the other option on the table. Since there were mad mods like FHD screen adapter for T430 and others, maybe it would be possible to craft a cable that would allow to connect a mouse dongle along the way, basically piggybacking on the original connector? Sure, it would require some controller to be added along the way, as AFAIK USB devices aren't supposed to be simply hot-wired, but there's a plenty of space around the battery area to do that.