Necessity of half-turn twists in the edgeless case
Determine whether every configuration accessible in the edgeless case using half-turn and quarter-turn basic twists is also accessible using quarter-turn and reverse-quarter-turn twists alone.
References
In the edged case, since a basic sequence is convergent if and only if it is twist-finite, there is no need for half-turn twists, they can all be replaced by two quarter-turn twists without affecting convergence. Is the same true in the edgeless case or are there configurations accessible only using both half-turn and quarter-turn twists?
— Solving infinitary Rubik's cubes
(2502.01650 - Tisdell, 30 Jan 2025) in Section 7, Open questions, item 4