Does not help.
All the current participants in the discussion have likely used tens of other APIs, and probably developed a few themselves. Unless you are willing to get into specifics of the Plus API -- past / present / future versions -- you are not taking the discussion forward.
Puneet, you are in an enviable position to add value. You are a big customer to Omnesys and others, as well as a big downstream service provider. Not so long back you were providing the API under discussion (or a product developed around it) to your customers. It is fairly obvious that an API that is hardly functional, and has no documentation, or support, should not have been released. If you wish, you or your technical folks, can contribute a lot here.
Btw, whose or which question were you addressing when you say that "want to call back order numbers from the API" ?