I've had this thread open for an hour deciding what I'd reply with, because I think it's one of those things again that goes against what Rega is trying to accomplish with it's lightweight but rigid as possible approach. But, assuming those posters in your linked threads aren't lying, there seems to be reason enough to at least try it your self as cost isn't too high.
Maybe because everything has a natural resonant frequency, and possibly Rega has all their parts "in tune" with each other for their desired overall sound, that lowering one or more of those frequencies will alter that "in tune" Rega sound, and you'll hear a change, and then decide whether you like it more or less than before. From light and lively to a darker dull sound maybe? I dunno.