Attribute rule to union buffers

Question

I've successfully created an attribute rule to add a new buffer to a polygon feature class (FC) when a new point is added to a point FC. However, now I need to dissolve all buffers in the polygon FC (named "bufferTest" in code snippet below) whenever a new buffer is added. Not sure if I need to add this to the attribute rule on the point FC, or create a second attribute rule on the polygon FC. The Arcade code to create the buffer is below. How can I union/dissolve all of the buffers into a single feature?

var bufferDetect = BufferGeodetic($feature, 0.5, "miles")

return {
    edit: [{
        className: "bufferTest",
        adds: [{geometry: bufferDetect}]
    }]
}