I found some success to specific PROBLEM statement above:-
The modal view is presented (added) to the same window so I simply brought my mini dashboard view in front like this..
UIWindow *appDelegateWindow = [[[UIApplication sharedApplication] delegate] window];
UIView *miniView = (UIView *)[appDelegateWindow viewWithTag:12221]; // 12221 is tag of mini dashboard view.
[appDelegateWindow bringSubviewToFront:miniView];
However, I'm still looking forward to your expert opinion about my approach and open for alternative approach considering orientation and other potential challenges I might get with this approach.
Next up - I am working on bringing my custom popover view in front of modal sheet. As of now, tap on mini view opens the message popover but behind the modal sheet.