8hp50/51 torque limits

As a new supra owner I have of course been looking at all of upgrades and performance options available however, considering the 8HP51 Is rated to Max 500nm, it seems even some of the common stage 1 and certainly stage 2 and higher hp/tq mods are a major crap shoot, completely unproven, and very likely to fail near term depending on use etc...

What am I missing?

500Nm is input torque rating - dynos measure torque at the wheels - which is multiplied by gear ratios, torque convertor, diff ratio and wheel/tyre radius. (i.e. Wheel torque is higher than input torque)

I have the same concern about the tolerance of 8HP51 gearbox.