I think you are asking to things which are not that important to you or else you know what they are for and if you do need it.

Yes, most of us is using a pressure chamber which is like a big empty fuelfilter which solves some pick-up issues with a full fueltank. The CPD is a way to get longer runtimes to reach 5 minutes without pitsstop as more divices are develloped like pressure gas coolers.