If you have a specific requirement that you are trying to improve in an existing application, then
you should be working along with what exists and try to find "compatible" designs that work with what you have. It will be "poor" design if you create a so-called "improvement" and it is not compatible with the existing application. For some individuals, this will take a significant amount of discipline and self-control.
So far, it sounds like your design concept is not compatible and will conflict with what exists today.
Aside, if the existing class has many constructors, in order to handle requirements, and you redesign it's constructors to work with a single argument, you are only moving the logic to the code that instantiates the instance of this class. Moving the logic that called a specific constructor to logic that creats your parameter object (or your Builder) is not much of a change or improvement and may not be worth the headache.