Z-stability for nonamenable actions

Prove that, for every amenable, topologically free, minimal action of a nonamenable group on a compact metrizable space, the crossed product is Z-stable.

Background

For amenable actions of nonamenable groups, nuclearity and simplicity can hold while the acting group itself is nonamenable. The survey states that Z-stability is expected to be automatic in this setting, but presents the assertion as an unresolved conjecture.

References

Conjecture 1.0.2 (Nonamenable groups). Let G ↷ X be an amenable, topologically free, minimal action of a nonamenable group. Then C(X) ⋊ G is Z-stable.

— Classifiability of crossed products  (2610.06586 - Gardella, 5 Oct 2026) in Conjecture 1.0.2, Chapter 1, p. 3