Hello! :)
If you check the details about the use of the plugin, you can notice that the effect is processed through a script call. This means that you can choose when using it. In other words, this plugin creates an extra transition system that is alternative to the default one.
About the sound, you can customize your sound through the options object that needed to be passed as argument of the script call.
For making you an example: let's take the situation that you want to process the warp to MapId 6 and use your door spritesheet (remember the sheet format of 12 x 6 frames) named "MyDoor" and you want to render the door at characterIndex 2. Moreover, you have your custom SE named "MySound". The script call for this situation will be:
var options = {
mapId: 6,
characterIndex: 2,
x: 12,
y: 12, // Those are the coords where the player will be transferred
sound_name: "MySound",
sound_volume: 90
}
this.doorTransition('MyDoor', options)