Howdy Meilin and welcome to the forums!

yes, there is no problem with that. most people in that situation would leave their wow normal size, just behind the active wow, set the fps to 5/30 (or whatever works) and just use PiP swap to bring the character you want to the front

if you have any other questions, please feel free to drop me a note.

have a great weekend,

Rob (keyclone developer)