It doesn't seem like Topaz's software developers will have any significant problem. They do a lot more difficult things than this. To a user, it looks like the information is gone, but to a software developer, it's just data that needs to be stored for later use. When the user clicks 'Done' for the mask, it would store the slider values for hue, luminosity, range, inversion, and the others in 'Adjust Mask'. Then when the user applies a saved Effect to a photo, it applies the mask also.
Would you find it useful if, for instance, a saved Effect would automatically mask out sharpening and local contrast in a landscape photo's blue sky?