As I recall the links I provided related to dipole mounted (open baffle subs), they had nothing to do with sealed boxes.
Compound loading only cancels a minimal number of the harmonics that drivers reproduce. It certainly won't account for the changes you say you're hearing. A more likely situation is that there were room placement problems that were helped by repositioning of the box.
Most likely it's just the slightly cleaner sound you hearing, especialy noticable to you (apparently) in the upper frqs where your meeting your mains forced (set small), or natural roll off when set large..
The freq response of the sub it's self should not change a bit, unless the sub posititon itself changed, your listening position moved, or you added eq-ing to the sub.
Any cancelation of harmonics (odd, even, etc,) with sub divers no matter how small, is a good thing.
As long as your happy, well thats what counts. So have you grown accustom to looking at that ther 10" basket sticking out and staring back at you?