Polynomiality of the stringy E-function for varieties with NCCRs

Let $X$ be a normal Gorenstein variety over $\mathbb{C}$ with a noncommutative crepant resolution (NCCR). Let $E_{st}(X,u,v)$ denote its stringy $E$-function.

Stringy E-function polynomiality conjecture. The stringy $E$-function $E_{st}(X,u,v)$ is a polynomial.

For varieties with a commutative crepant resolution, polynomiality follows because the stringy $E$-function equals the Hodge polynomial of the resolution. The conjecture asserts the analogous conclusion for NCCRs; the source notes that the corresponding statement fails for twisted NCCRs.