Xume magnetic filter holder?

[MrDrizz]

Just wondering if anyone has experience of the Xume magnetic filter holder?
I'm very tempted by it for use with the 10 stop nd which is a screw on, found it a pain having to unscrew it ever time I had to recompense a shot.

Also don't really know how bad the vignetting will be with my Samyang 12mm.

 

[chris malcolm]

You should be able to avoid the vignetting by first fitting a step up ring, then adding the Xume stuff to the end of that. How much to step up? Your guess is as good as mine, but having the lens and camera your experiments will be a lot better

 

[MrDrizz]

I've looked more and it'd be cheaper to just get the cokin nausea 10 stop