I would like to share my app to give some inspiration what you can do when combining web bluetooth/web hid api and with .3d/vr using babylonjs.
With the ergometer-space app you can row in 3d / VR using an concept2 ergometer. The app can do many things and the 3d/VR part is made with babylonjs. You can row live against other online rowers or a pace boat. There is also a mini shark game where you are being chased by a shark.
It is all made just for fun, there is no commercial goal what so ever. You can look at it on the following website ( or download the ios/android ergometer-space app)
If you do not own an ergometer you can select demo replay from the menu to let the rower move.