Is there such a thing?
Is it like a new pair of shoes, where they may be the right size and fit, however, they still feel stiff, until they are broken in?
If so, how long does it generally take to break-in a wetsuit? Also, is there anything that can be done to expedite this process aside from just more OWS?
Thanks in advance for any info.
The wetsuit is officially broken in the first time you pee in it.
There is no break in time for wetsuits.
Yep, two kinds of triathletes; those who pee in their wetsuit and those who lie about it.
There is DEFINITELY a break in period for wetsuits. Depends a lot on the suit, how it fits you, the type of rubber, stitching, etc. But ALL wetsuits will stretch-permanently-some in the initial wearing period. If you are wearing a tighter suit, then you’ll need more time to stretch it out than if it fits you more loosely. But the shoulders will certainly stretch some as well. I’d say that putting it on/off probably does as much to stretch the suit as swimming, but that’s just a guess from my experience. Likewise there’s no set amount of time. But, yes, every wetsuit will stretch permanently to some extent from use. How much? And how long? There’s no one answer.
I think there’s definitely a break-in period for the wearer too.
We’ve all seen that guy on the start line with bandages on their neck…a tell-tale sign of someone who tried their new wetsuit on for the first time yesterday 
To me it always seems like a good idea to give a wetsuit its first swim or two in freshwater, rather than immediately bombarding a virgin wetsuit with chlorine or salt. I don’t know if there’s science behind it, but I don’t see how it can hurt!