I'm not sure I understand the second rule. I appreciate the rules being given without words, but it's...is it saying that gray squares must appear in rectangles? Or something else?
There's an undocumented feature where you can click a rule and it'll check only that one, so you might be able to experiment with that and figure out the rule. ROT-13 spoiler: gur ehyr qbrf abg gnxr mbar obhaqnevrf vagb pbafvqrengvba ng nyy
There's an undocumented feature where you can click a rule and it'll check only that one, so you might be able to experiment with that and figure out the rule for sure if you haven't already. ROT-13 spoiler: lbh ner pbeerpg, tebhcf bs pbaarpgrq tenl fdhnerf zhfg or erpgnathyne