Add cascading styles from header to mobile

(Submitted by Joe via Case #2791)

Curious if you can add this functionality to the next update of Divi Header Customizer...

Can you have it so the styles we set for each header cascade down to the responsive sizes? We really shouldn't have to re-enter literally everything for every responsive size. That seems really cumbersome. We really should only have to enter the values we wish to change on the responsive sizes - not every single thing. Font choice, color, letter spacing, style, etc - all should carry over.

Would really appreciate it if you could add this on the next update