Back in 2003, Chicheng Zhang released Games::Literati to handle Scrabble and the Yahoo!Games clone called "Literati". In 2016, I took over maintenance, and updated it to fix a couple of scoring bugs, and to handle Words With Friends (and Super Scrabble, which has a bigger board and more tiles). My guess is that the word-searching itself is not as efficient as it could be (I just kept CZ's search intact) -- and maybe not even as good as what you've shown -- but it does present another way of doing things.