With the higher compression vs the TT Sups, with the alcohol injection its all about scanning, there is no magic number. But I would figure from what I've seen with NA conversions with FMIC and no alcohol able to run 8psi or (.55bars) to 12psi or (.82bars) God I hate bars
with a T04E-60 on 100 octane then a vehicle running 50/50 or 100% will be able to run the same as the one with the FMIC. I think you go with 440cc injectors on most of the base Single turbo upgrades for the NA supras.
You have a bunch of other factors like downpipe size, fuel pump, intake, timing curve, fuel curve that play a role in how much you can push it. If you dont have a wide band I would not go to far beyond the stock kits specs.
Because your getting the intercooling plus race gas with the alcohol injection you should be able to push it further but you don't want to tune beyond the margin of safety.
Can't see the youtube vid from this PC but I'm assuming you have a FMIC.