If you were having true sway issues before the propride, then what you are feeling is the propride fighting that sway. I'm not a big fan of using a device to stop known sway for just this reason, but to each his own.
The trailer is still trying to sway, so any measures you would have taken aside from the propride to stop the sway, will help to improve that feeling. More tongue weight being the easiest and most obvious.
If you feel you can put up with the inconsistencies, and are confident that the propride will not fail on you at any point in the future, leaving you hundreds of miles from home with a trailer that cannot be towed without a mechanical device to hold it in line, then do nothing.