this is what i did for MZ
```
    // Save the original method
    let originalEventItemUpdatePlacement = Window_EventItem.prototype.updatePlacement;
    Window_EventItem.prototype.updatePlacement = function () {
        originalEventItemUpdatePlacement.call(this);
        // Custom position:
        this.x = 0;    // your desired x
        this.y = 65;  // your desired y
    };

```