There is a massive difference between a backup dancer and Lisa. Although I agree a rap verse in between will be fun. But having having Lisa and not dance with her would be incredibly stupid. And Lisa can and rap at the same time very well.
You're not getting it though...
If the only thing she does is Dancing then IKON could just get just get Jennie as both would fill the role as Back Up Dancers to whatever IKON does.
So basically I am saying is that IKON should have Lisa as a Main/Lead Rapper in the Song because that's what will turn the group performance on it's head