Recently, I came across the article Realization of efficient quantum gates with a superconducting qubit-qutrit circuit where its authors proposed a physical implementation of three qubits quantum gates with two physical qubits and one physical qutrit controlled by microwave pulses.
As a result, they were able to implement physically CCZ gate which when accompanied by two Hadamards implements Toffoli gate.
They also proposed configuration implementing Fredking gate, another three qubits gate which together with Hadamard gate form universal set.
Finally, they showed that their design can be used for implementation of $CC-U$ gate, where $$ U= \begin{pmatrix} \cos(\theta) & \mathrm{e}^{i\varphi}\sin(\theta)\\ \mathrm{e}^{-i\varphi}\sin(\theta) & -\cos(\theta)\\ \end{pmatrix}, $$ which is more or less similar to $U3$ gate on IBM Q (to be precise $U(\theta, \varphi) = U3(2\theta,-\varphi,\pi+\varphi)$).
As it seems that this proposal is able to cut lenght of circuit, particularly in case of Toffoli gates (implemented by physical CC-Z gate and two Hadamards only) and therefore enables us to implement more complex cirucits, I am curious if such design is being implemented or at least considered by companies like IBM or Google for their next generation of quantum processors. I highly appreciate any links.
