In my newly thought over opinion I suppose its rather good they have the Pickup Discharge rule.Trains coming into New York City are packed(especially from New Haven)It wouldnt make since to cram more people on in NYC when they can just take the transit systems DESIGNED for NYC instead of the one that just SERVES NYC....its probably wrong....correct me if im wrong....remember its just an opinion.Instead of making a ride into GCT crowded and unpleasent just because you wanna faster ride.Trains meant to do Inter-city service between NYC Stamford and New Haven shouldnt have provide local sevice within the city limits that would make it a Subway If you buy equipment for service in your state you dont want it making local service in another state The Hudson and Harlem lines are operated solely by MTA the NH is a joint between MTA and CDOT so both states would have to agree to it making more NYC stops....currently it only makes a stop in the Bx so it can service Connecticut.
Remember, too, NH trains, due to CDOT's foot dragging for years on fleet replacement and expansion, are especially crowded.
I think the Harlem line does a good job of servicing NYC stations along their shared ROW, but I think you could make a case that there's a need for a reverse commute option from the Bronx to Westchester and CT. I'd add Woodlawn as an "R/D" stop. Fordham's crowding, I think, isn't just students, but reverse commuters already using it for reverse commutes (and let's face it, the 60 or 61 Bee Line buses don't get it done). One additional stop in the Bronx would help.
I don't think you should change the R/D nature of the NH stops in the Bronx (they serve a purpose: they're not intended for intra-NYC service), but it would gum up a heavily travelled corridor.