Echo Dot v3 - Flush mount box

I wanted to ceiling mount an Echo dot in the bathroom and this is what I have come up with. It's print in place, including all supports (I tried slicer supports but this was way more efficient on material and quicker to print). Simply make a hole with a standard 127mm or 5inch hole saw, feed your power cable through the side entry on the mount, push the mount into the hole, push the tabs out, then use normal M4 or size 8 screws to pull the tabs tight and grip the plasterboard/drywall. Then i