I'm sure there should be no functional issues, I just wonder if the rifle buffer isn't smoother shooting due to the longer spring. The laws of physics, I believe, would indicate that the longer spring will dampen the recoil impulse by spreading it over a longer mass, but what I don't know is if it is a perceptible amount.
I'm trying to build a low budget yet super soft shooting AR. I can't afford a lightweight BCG or anything fancy, but a rifle buffer assembly is easily affordable.