I saw that Kamp (@KampCreates) posted on Twitter/X about creating his own controller based on the Steam Deck's gamepad. He showed it off as a 3D model, and it would have all of the inputs that the Steam Deck has, including the back buttons, and would function largely the same. This model looks exactly like the one Kamp showed off and even already 3D printed and built.
Valve fans have been treated to not one but two new hardware leaks today. The second product now in the firing line is the Steam Controller 2, which has been nicknamed the Steam Duke on account of its large proportions.