Nice idea, pitklad, but I don't think it would work.

The thing with 'hide' morphs is that additional morphs might be applied to the hidden part, causing it to come out of hiding. This would not typically happen for brows, unless one made a really oddly shaped alien head, but for toe JCMs it would almost certainly would, as feet are not vaguely ball-shaped like heads.

Of course, a variation of your idea might work to fix those welding problems. The default shape could have the boundary of the toecaps inside or outside the foot geometry far enough to avoid welding accidents when exporting or importing. Then a morph would be applied to that in order to put them back in a useful position.

I'm still thinking though that if I have to resort to tricks like that, maybe it's better to just keep the toecaps separate from the main geometry.

-- I'm not mad at you, just Westphalian.