How to create a custom rerender on a lightning component bundle? 213376

Child_213329.cmp

<aura:component description="TestChild">
    <aura:registerEvent name="fromModal" type="c:Event_213329"/>

    This is for testing 
    <lightning:button label="Call Parent"
                      onclick="{!c.callParent}" />
    
</aura:component>

Child_213329Controller.js

({
    callParent: function (component, event, helper) {
        var evt = component.getEvent('fromModal')
        	.setParams({
                "message" : "A component event fired me. " +
                "It all happened so fast. Now, I'm here!" })
        	.fire();
    }
});

Event_213329.evt

<aura:event type="Component" description="Event template">
    <aura:attribute name="message" type="String"/>
</aura:event>

MidParent_213329.cmp

<aura:component implements="flexipage:availableForAllPageTypes,flexipage:availableForRecordHome,force:appHostable,force:hasRecordId">
	<aura:handler name="fromModal" event="c:Event_213329"
                  action="{!c.fromModal}" />
    
    <aura:attribute name="message" type="String"/>

    <lightning:button label="ShowModal"
                      onclick="{!c.showModal}" />
    
    <hr/>
    message: {!v.message}

    <lightning:overlayLibrary aura:id="overlayLib"/>
</aura:component>

MidParent_213329Controller.js

({
    showModal: function (component, event, helper) {
        $A.createComponent("c:Child_213329", {
            "fromModal": component.getReference("c.fromModal")
        },
            function(content, status, error) {
                if (status === "SUCCESS") {
                    component.find('overlayLib').showCustomModal({
                        header: "Child",
                        body: content,
                        showCloseButton: true
                    });
                } else {
                    throw new Error(error);
                }
            });
    },

    fromModal: function (component, event, helper) {
        var message = event.getParam("message");
		console.log('message from modal', message);
        component.set("v.message", message);
    },
    
    genericCalled: function (component, event, helper) {
    	alert("genericCalled");
    }
});