The cancellation conjecture for effective Chow motives

Let $k$ be a field, and let $N$ and $M$ be effective Chow motives. Write $[N]$ and $[M]$ for their classes in the Grothendieck ring $K_0(M_k)$ of effective Chow motives, and let $A^*(N)$ denote the Chow groups of a motive $N$ with rational coefficients.

Cancellation conjecture for effective Chow motives. If

$$[N]=[M]$$

in $K_0(M_k)$, then $M$ and $N$ are isomorphic. In particular, they have the same Chow groups with rational coefficients.

The claim would remove the finite-dimensionality restriction in the preceding cancellation argument, where equality in the Grothendieck ring only yields stable isomorphism and equality of Chow groups after adding a motive with finite-dimensional Chow groups. The source gives no resolution of this conjecture.