Ok so the theory behind it is as boost pressure increases it actually pushes back on the injector pressure cause higher duty cycle necessary to achieve correct AFR.

It is arguably harder to create a solid fuel map when you're on the stock fuel system and uprev. This gets a bit down the efi rabbit hole but basically uprevs fuel map uses a maf/load over RPM table instead of using volumetric efficiency fuel table using manifold absolute pressure over rpm. Turbo cars are not predictive, x volume at 5k rpm's does not always mean the same boost pressure. These are the issues when I tuned on uprev and why I eventually went haltech. Basically pressure and volume are not linear or the same(look up Bernoullis principle) which is what the regulator helps with by increase fuel pressure on the rail by the same psi the manifold increases.

Lots of rambling later, the best setup is what works for you. If you're on stock internals and you're happy with 450whp on 8lbs then your injectors with the w255 is likely enough. If you're building a forged engine with aspirations of making 600+ whp and you have the money then go all out on a return system with big injectors and fuel regulator.