Conditional statements in formulas can be helpful to define different family scenarios in Revit. Currently, they can not be applied to every type of parameter.
I would like to introduce the idea of extending this functionality to the Family Type Parameter, which would allow the type of nested family to be controlled by the conditional statement (IF formula). The nested family type could be chosen based on other conditions in the family.
This functionality would avoid creating new types of families, avoid increasing the size of families and help keep the project size reasonable.