There are algorithms that are more efficient than the typical speed cubing methods, but are based on large amounts of computation, rather than pattern matching, thus unfit for humans.
Get a faster computer and a larger cube, the trade-off is likely worth it. A rubik's cube isn't such an intractable problem, I doubt a computer can't solve it faster than a human: in the worst case, they can rely on the same algorithm. Then, they can try to find shortcuts or just shorter paths.
I always thought minimizing the number of moves was the goal, hence "more efficient" made sense to me too.
Rubik's Cube solution unlocked by memorising 3915 final move sequences[0].
> For the first time, a speedcuber has demonstrated a solution to the Rubik’s cube that combines the two final steps of the puzzle’s solution into one
[0] https://www.newscientist.com/article/2334632-rubiks-cube-sol...
More efficient in terms of rotations necessary to solve the cube.