I bought the Power Magic Pro to install with the Blackvue DR750S Dashcam as I had a recent experience of my car being damaged in a carpark and want to use Parking Mode from now on. Hardwiring the camera with the Power Magic Pro was straightforward, following the instructions and a couple of YouTube videos I found for my specific vehicle (2017 VW Tiguan Mk2). I recommend you use fuse taps to connect the Power Magic Pro to the fuseboard - bought those off eBay.
Since installation a week ago, the Power Magic Pro has worked flawlessly, allowing the camera to record in Parking Mode with ignition off, but switching to direct power when ignition is on. So I highly recommend this product for hardwiring your Blackvue Dashcam (not sure if it works with other brands, but can't see any real reason why it wouldn't - however, do your research and talk to Strathfield Car Radio about that).