Screenshot size in VR Mode broken (?)

Description:

I'm currently trying to create programmatically a screenshot from a mobile device (in this case an Android device w/ Google Crome). Following the documentation I tried using the following code in html

<a-scene screenshot="width: 480; height: 360">

to set the desired dimension and then

var canvas = document.querySelector('a-scene').components.screenshot.getCanvas('perspective');
console.log(canvas.toDataURL("image/jpeg", 0.5))

While this works perfectly fine on desktop and mobile (not VR), in the VR mode the screenshot function actually captures the screen from the bottom left point of the canvas (0,0) to the size I specified (height: 360, width: 480)

Is this a desired behaviour? If so, how can I change my code to capture the canvas focusing the center of it?

• A-Frame Version: 0.9.0
• Platform / Device: Android

Start at the a-scene screenshot component and the getCanvas('perspective') entry point described in the report. Reproduce the configured 480x360 capture on Android in VR mode and compare its canvas origin with desktop and non-VR behavior. Done means the requested dimensions capture the centered view rather than the canvas's bottom-left region.