I don't use baffles if that is what you mean in a couple of my sumps.
The most important function of the baffles is ;
#1 gas exchange(releasing co2
to keep ph proper)
#2 keep your skimmer running perfect all the time.
If the level of water the skimmer pump is in changes then that CAN effect the flow of skimmer.
That being said all my skimmers(even one on sump with baffles) has pump in a uncontrolled section.
Whether they are needed I can't say with proof,but I will say EITHERWAY that I always want the biggest area of my sump to be where the return pump is located.
This allows the most time between top offs if you are not using an ATO(I don't).
Gas exchange should be able to take place at the overflow or upon entering the sump IMO
,after that it is all up to what people want to do in there filter.
Many use Rubbermaid tubs with just protein skimmer, calurpae and eggcrate to keep it out of return pump with no baffles at all.