New attribute for cast members should be added

I have a new idea that should have already been added to IMDb attributes for cast members. The idea that I am talking about is that a new attribute called understudies should be added onto IMDb. This is due to the fact that multiple theatre performances on IMDb like spirited away live on stage, life of pi, the prince of Egypt, Les Miserables and much ado about nothing live on stage and may more. Due to this IMDb should add understudies as a new attribute as those cast members are a key part to any play ever made and therefore should be on the website as a new attribute. Hope you like and approve my new idea