These are awesome, nice work!
Any chance you'd be willing to add an option to allow for snap (not screw in) mounting? Either some sort of friction fit similar to this:
Or even better an actual snap in similar to this:
There are some fans on a few printers (like Wanhao i3) that it would be extremely useful for since the screw mounting isn't easy. I am able to find a few options but I like your customizable grills SO much more!