Well, just because they were fold-downs does not mean that they were not balanced to sound good, or even superior, after they were folded down.
And having it folded down prior to LP pressing is better than hitting the mono button on the stereo, because all of the information is spread out over the entire spectrum, rather than being read from one-half of the groove. No real difference, though, with a stereo CD folded down in that regard.
I always prefer Blue Notes in mono, and would always spring for a mono LP over a stereo, fold-down or not.