Impact of downgrade an Angular Component

Question

Hello,

 

Hope you all are doing well. Coming to the point recently I got an opportunity to use Angular7 component in existing AngularJS application. So, I downgrade the component to work with AngularJS application but my question is what can be the impact of downgrading an component. Is there any performance impact or anything ? I don't know exactly what I can lose by downgrade an component.

 

Please let me know if you have any idea on this.

 

Thanks.