Body Swap AU.
It's family dinner night and on thst same night Grandpapi (Who forgot) plans to use a machine that will swap his body with the mayor's so he can take over Miracle City. Rodolfo tries to stop him, Manny is turned, and the interference leads to the machine breaking but not before it swaps Manny and Rodolfo's bodies and Frida and Maria's bodies.
Now while Grandpapi tries to fix the machine the Rivera family and Frida has to spend a few days living different lives and learning more about each other. Such as Rodolfo and Maria learning what their son and his friend have to deal with due to bullies and the biased Chakal and Manny and Frida learning how much responsibility and hard work the superhero and librarian have to do everyday.
There's also going to be some hilarity ensuing such as Sergio, Dr. Chipotle Jr, and Zoe becoming crazy jealous due to seeing Rodolfo (In Manny's body) acting lovestruck around Maria (In Frida's body).
And Manny (In Rodolfo's body) and Frida (In Maria's body) doing whatever they want because now they're physically adults.