Yes, Polygon in The Times and similar 'word wheel' puzzles almost always disallow plurals. When faced with a Wordle choice I usually weigh up which word is more likely in American English. I got today's word in five but I associate more with Australia.
As for devil not Satan, this follows the Scrabble rule about words which have to be capitalised. You can't use England or English, for example.
When Mattel (company owning Scrabble) recently banned 419 words, mostly slurs considered racial or homophobic, I was amused that some words, such as dyke, escaped the ban because of an alternative 'acceptable' meaning. This attempt to make the game more 'family friendly' paradoxically still allows the four-letter f and c words.
In a recent game of online Scrabble my last opponent had played SHITE (permitted) going down to a triple word square. I had great delight in prefixing it with GOB from the triple word square above.