The characteristic variety conjecture for solution sheaves

Let $\cM$ be a module over the sheaf of convergent-exponential differential operators $\cD^{\mathrm{ce}, \Lambda_0}$, with characteristic variety $\mathrm{Char}(\cM)$ and solution sheaf $\mathrm{Sol}(\cM)$. Let $\mu supp(\mathrm{Sol}(\cM))$ denote the microsupport of the solution sheaf. The characteristic variety conjecture. Although not used in the paper, the characteristic variety should satisfy

$$\mathrm{Char}(\cM)=\mu supp(\mathrm{Sol}(\cM)).$$

This is presented as a useful observation rather than developed or proved in the paper; its resolution is not specified in the supplied text.