Elaborating along this previous question, could you please invalidate this ICE design with solid authoritative arguments explaining all the flaws?
Whatever the purpose, one single large coaxial valve is better at effortlessly filling or emptying one cylinder, compared to 2, 3, 4, or 5 valves per cylinder's head.
For a four stroke cycle ICE to work it requires a system that involves (or replicates the behavior of*) at least two valves, intake and exhaust.
If maximum cylinder head's surface is occupied by one (exhaust) valve**, the other (intake) valve could be embedded in the piston.
Maybe a better filling/emptying performance can outbalance a complex internal valve design.
Conceptual animation, please imagine a gear train of five smaller gears instead of three, in sandwich between bipartite connecting rod, so that they don't collide with anything.
Notice the natural variable opening and closing speed of the intake valve due to combined motion of the whole system around crankshaft's pin. (closes faster than it opens, (cam rotates contrarotative to crankshaft)
Intake valve does not need a counterweight to balance itself as it is meant to be either locked closed, or its opening/closing is helped by inertia, still the whole piston-valve-connecting rod system has to be balanced with a crankshaft counterweight. (all of this missing in the animated gif below)
*ports at the bottom of the sleeve / sleeve valve (bristol-like)
**spark plug somewhere