Ok, the 4090 mobile card that I got does indeed look like a ZRT not look like a ZRT and is instead a X-Vsion card. I've used the CH341 bios programmer to download a copy of the vbios for @SuperMG and he has confirmed from the vbios extract as well.
Work meeting ended a bit late. I will install the card tomorrow and test it with the Optimus M6800.
I am no longer testing the card in the LVDS M6800 as I was also intending to deploy it in a eDP M6800 which is now not possible without the EDID hack. I have initiated for a full refund and return of the card with Taobao. Unless the seller really confirms that he has a ZRT version with proper pictures and video to backup his claim, if not I'm not getting the 4090 from him anymore. I will instead deploy the P5200 to the eDP M6800 I am building. @SuperMG the P5200 will work with the eDP M6800 right?
*Edit: On closer look, it is an X-Vsion 4090 MXM card and not a ZRT version. It is going against the confirmation by the seller and I have initiated for a full refund.*