That the CoSi single-crystal sheets can have a lower resistivity than copper is conceivable. But the fact that the interconnects need to be single-crystal add significant complexity to the fabrication of real-world interconnects.

Further, resistivity is not everything. What is the maximum current density in the material, from a degradation point of view? Maybe that is meant by "current-carrying capacity", but that should be made more clear.

"transmit signals without lag "? It seems that any length of interconnect will lead to signal lag.

The ring oscillator frequency is usually a measure of delay in the active inverters, with only a small contribution from the interconnect. This is why I find that experiment not very conclusive.