I've asked myself the same question since I got my Aurion years ago...and I always end my thought on the same two things.
1. It's FWD. The power you can gain from a 2GR-FE engine with the limited space under the Aurion's bonnet is pretty difficult to manage. Atop that the chassis isn't built for it. But the most triggering thing to me, is that no matter how hard you push the 2GR and chassis, it's still a FWD car and that power is great while you have traction...but it's hard to put it down on launch and it's gonna' be even more difficult to put it down around a corner without going straight into a wall. Also with the weight of an Aurion, it won't be too kind going around sharper corners. Thiccccc girl got roll.
2. It's automatic. Sure the tiptronic/sports mode is a blast and always gives you an edge for holding those revs with more control...but it's still not a manual car. Let's be honest...stick shifts are life for car enthusiasts. I'm excited that my project car is a manual. I still haven't seen any references or proof of anyone successfully doing a manual conversion on an Aurion (which would also include moving the foot parking brake).
Though it'd be wicked to see an unleashed Aurion. If someone spent the infinite amount of time, money and skill to do a super unlocked Aurion, you'd have to take a step back and see what would make the car wicked.
RWD/AWD (I'd prefer RWD for drifting because why not), Manual gearbox, and a supercharger or turbo, because if you're going through the effort you wouldn't leave it NA. Not to mention you'd have to flash the ECU to cancel out the O2 sensors on the header cats.
It'd be a whole rework of the entire car, and while (I think) it'd be sexier than a Chaser*, it'd be so over-engineered you'd end up having to strip all the interior, have panel gaps, probably lose air con for bonnet space, you'll have the Aurion community up in arms for ruining a good car. I do think it'd be an awesome thing to see.
(*everyone loves a white chaser)
One other thing to note, if I was to ever use an Aurion (AT-X) as a track car (because I love Aurions), I'd just weight shed it and remove all sound deadening, put wider tyres on, coilovers, strut bars and put BRIDE seats in.