Sizing question, what to expect.

So I recently bought an older Volks set from Mandarake and saw after I had already ordered that the sizing lists it as compatible with DD (M/L) and DDS (L only)  

It's the Classical rose waltz set seen in that link, but I'm curious as to why it would be such a difference when there's only a 1cm difference in bust from DD and DDS mediums.  I had intended it for a DDS M chest girl, but now I'm worried about the fit (it's still in transit, or I'd just try it on her).  Does anybody know why this would be? 

Edited October 13, 2020 by DesertPhantom51

Hmm, my only guess is that it might be a smidge loose on a DDS chest due to the darting on the blouse& vest...?  My only guess is that they said it's not compatible with DDS M bust is because they intended the blouse& vest to fit rather snug. Personally I wouldn't worry about it unless you want the blouse to fit like a glove. 

Yeah, that makes the most sense.  I was just paranoid there was going to be some kind of torso length difference or something else I hadn't considered.  Thanks for your response.