Thanks for all the feedback. I don't see a reason why we couldn't/wouldn't provide VR capable Web Standalones in the future which also take external Bluetooth controllers as input device. Our Web Standalones in general are still being improved further and further with time - we're adding more features and improvements pretty much constantly.
As blutetooth controllers are an extra gadget both to buy and setup (it ain't that straightforward!) I'd recommend usingt the tap-drag joystick feature that already works. Although you cover part of the screen while doing this.
Also adding a feature like the Google Earth VR like feature of magnet clicking to move forward in Cardboard-views. You can't strife or move up/down vertically.
But you can always turn around to go back, up and down. It's simpler to implement and is tested and works. It might even be familiar.
Even a simple working movement controll to begin with would be much better thatn it is at his point.