Bored in class again, ill try to help 'show' the issue, or advantages let's say, that have changed.
The xrr on r2 tires will be faster start of stint, but why wouldn't it? It has less fuel. The counter advantage for the fzr is that it has 'better' tires. Also as the stint runs to the end, the fzr and xrr weight due to fuel is much more similar, and that is when the fzr will shine.
On tracks like we1 and possibly as6r, the xrr will most likely run r3 tires compared to fzr in its r2/r3 tires. Sure once again the xrr might be pretty quick start of stint because of fuel, but the fzr will turn that around end of stint on lower fuel and most likely better tires.
The xrr still has the disadvantage of being able to flip and the only one to get stuck in the gravel.
When balancing the xrr/fzr no one normally thinks about the fuel advantage, even in gr1 balancing. When you want xrr/fzr to be even, most only run the first 25-50% of a stint to see the xrr slightly quicker or both cars even, no one ever drives the full stint to see the fzr burn off the fuel and have the better looking tires end of stint to reel in the xrr.
Finally to add in the factor that when xrr has r2 tires, the fzr can stretch its stint if it is using r2/r3 tires. There's many things you have to factor out when balancing, and q times are about 5% of it.
The test race is there to test the restrictions, because we won't know how it is in racing conditions until we put it in race conditions. Deko already said there's another test race after this, the official one to test teams iirc, so don't jump to conclusions just yet. Let's test it properly, and we can then easily analyze which restrictions will probably be for the best.