I seem to remember a guy you know very well with the initials R and W made an alternative to the GSR kit a few years back - to say it flopped was an understatement.
A larger bob is only part of the equation.
Going on your principles, the 'focus kit' available for mpi Seicento and Punto 8v's would be better than the GSR as it utilises a larger bob size.
Going on your principles that a less restrictive bob is better : why did the Focus kit get comprehensively beaten by the GSR in a straight shoot out on the same car at the r/r.
You have probably read already but :
https://www.fiatforum.com/punto/211645-focus-induction-v-gsr-induction-result.html
Also the other equation is torque, unless you are able to neglect this rather important factor will the kit also gain substantially in low down torque? If not then this will be no good for anything less than a race type engine which spends its life at 6K rpm+
Sorry to question, but I have seen so many similiar products come before and fail, what is going to make this different?
Better solutions to the SPI induction kits have also had their day as the last of the spi cars is nearly ten years old and the primary market has passed.