https://www.youtube.com/watch?v=b_RdSEIhaRY
The above video is not mine.
A bideck snowskate is like a skateboard deck mounted above a mini snowboard. There are powder specific models. I have a chillerdeck and use it in flats with out a leash. It's pretty cool to be strapless on snow.
For icey or crusty conditions it is not good, not much leverage or control over the edges with out any bindings.
Its a Powder toy.
I built something like this but bigger, it works pretty well in icy conditions.
My first build was on a 155 snowboard, that was too big, the second was on a 125ish and it was more managable. I sized the deck widthwise so that it wouldn't drag when it was leaning over about 30 degrees. I lammed two pieces of 1/4 inch ply together and pressed them to get some concave, then shellacked a little sand onto the surface for grip.
I don't use it much, it has kind of limited application I think mostly based on snow conditions. In southcentral AK we have lots of thaws through the winter, with some big dumps of various weights, and when I took it out in mid to heavy snow it would load up between the boards. That issue may be addressable thru the right wax or hydrophobic coating but even in non-loading snow I thought it was a little difficult to square the kite pull and the edge to edge riding. Easy to ride a standard heel side or toe side line but when carving the board downwind there was a big unpleasant loss of balance when you're not balancing a lot of weight against the kite yet not able to direct the board well, as you are losing a bit of fine control to kite pull.
The one environment where it was pretty cool was the local lake, which is sea level and doesn't hold good snow for very long. Whenever there is snow the local kids rally every square inch in trucks and snow machines leaving a shit surface which then hardens. Strapless with a bideck on that surface is one of the best options. The combined flex of the two decks buffers the chatter so it's more comfortable at speed than a regular snowboard, also you can shift weight to focus on just the bit of edge that is really working well for you. Heelside to toeside turns are gratifying, riding toeside becomes easy. Sharp edges are important. Gybes are easy and similar to a surfboard on the water, if a guy was into doing tack variations it would be fun.
In the big picture the board doesn't allow for big laid out turns at speed or fast cuts through terrain which is why I ride. Now I skip the lake and head for the hills strapped either on a traditional snowboard or reverse camber reverse sidecut board.