Hi,
the Polar Pro Shutter 5-Pack Cinema Series for Inspire 2 does offer ND4, ND8, ND16, ND32, and ND64.
https://www.polarprofilters.com/products/inspire-2-nd-top-nd-filter
but they are not Quartz Glass. I‘ll report as well how color accurate etc the ND32 and ND64 are.
Cheers
Chris