i making somekind of puzzle game now.
and i made =(Transfrom) module (attached).
usually when such simple things are not presented in the release or at the forum, that means there is much more easy way to do the same.
looks nice - seems to me as simple as you can get :)
you might achieve some slight performance gain by not using a spectral +, but a spectral AND at the bottom. then you have the boolean output directly and don’t need to check if the sum is 16.