Extend the method to exceptional complex reflection groups
Construct suitable $W$-stable multiarrangements and prove the coinvariant phenomenon for exceptional complex reflection groups beyond the non-exceptional groups $G(m,p,n)$.
References
Two natural questions for subsequent work concern possible generalizations to exceptional complex reflection groups and possible approaches to questions of for $\ell>1$ in the same way, making use of suitable multiarrangements of subspaces of codimension $\ell$, as well as the associated logarithmic vector fields and the arising Lie--Rinehart homology. It is not yet clear to us whether these questions, especially the second one, have promise, but they are certainly worth examining.
sixteen of the nineteen irreducible rank two cases, that is, all except for $G_{12}$, $G_{13}$, and $G_{22}$ (we do not know if that is related to the fact that these are precisely the rank two cases for which natural Saito structures do not exist Sec.~9.4.1)