Prodigy Advance System question

While going through my research on DCC I came upon an article from Tony's train shop regarding the power of the system being 2.5 instead of 3.5 amps. And that MCR the maker will upgrade the system if you send it to them to use 5 amp power supply, which Tony's sells agood 5 amp replacement. The article seemed dated so I wondered if this is still true? secondly if I replaced the original 2.5 amp power supply could I use the 2.5 to power a booster or something? i want to run several "Power district" as refered to in the book. ie:separate isolated blocks of power. It seems doable but is it. I think I would still need another booster to use with it.