Copy a Selection to Track Below

Check out my package AAF ORGANIZER - COPY/CUT to Target Track inside you'll find a template called Vertical Clip Move TEMPLATE create your own preset with your desired settings and enjoy!

This should do it:
(Be sure to read the comments to modify which destination track is selected)

//To change which track below the selected track to paste to, change the value of trackIndexOffset
// ex to paste to third track below the selected track, use  trackIndexOffset = 3
// You can use a negative number to paste to tracks above selected track

// This script assumes that link track and edit selection is turned on (SF requires it for scripts to work)
// and that the track width is the same on source and destination tracks

const trackIndexOffset = 1

//Function to check if PT is recording
function isRecording() {
    const transportViewCluster = sf.ui.proTools.mainWindow.transportViewCluster;
    let recordButton = transportViewCluster.transportButtons.buttons.whoseTitle.is("Record Enable").first;
    return recordButton.value.invalidate().value.endsWith("Is Recording");
}

sf.ui.proTools.appActivateMainWindow();
sf.ui.proTools.mainWindow.invalidate();

//Get visible track names
const visibleTrackNames = sf.ui.proTools.visibleTrackNames

//Get selected track name
const selectedTrackName = sf.ui.proTools.selectedTrackNames[0]

//Get the index of the selected track
const selectedTrackIndex = visibleTrackNames.indexOf(selectedTrackName)

// Get the paste destination track name by increasing the selected track's index by the value of trackIndexOffset
const destinationTrackName = visibleTrackNames[selectedTrackIndex + trackIndexOffset]

//copy selection
sf.ui.proTools.menuClick({
    menuPath: ["Edit", "Copy"],
});

//Paste routine if PT is recording
if (isRecording()) {
    //Use keyboard to navigate to destination track
    sf.keyboard.press({
        keys: trackIndexOffset > 0 ? "semicolon" : "p",
        repetitions: Math.abs(trackIndexOffset)
    });

    //Paste on destination track
    sf.ui.proTools.menuClick({
        menuPath: ["Edit", "Paste"],
    });

    //Use keyboard to navigate to original selected track
    sf.keyboard.press({
        keys: trackIndexOffset < 0 ? "semicolon" : "p",
        repetitions: Math.abs(trackIndexOffset)
    });

} else {

    //If PT is not recording use this:

    //Select destination track
    sf.ui.proTools.trackSelectByName({
        names: [destinationTrackName],
        deselectOthers: true
    })

    //Paste on destination track
    sf.ui.proTools.menuClick({
        menuPath: ["Edit", "Paste"],
    });
    //Reselect original track
    sf.ui.proTools.trackSelectByName({
        names: [selectedTrackName]
    })
}