[oliwary]

Fun analysis! I run https://squareword.org, which has 5x5 letters featuring words both down and across. Guesses are applied to the horizontal words, but the vertical words can be used as support, a bit like in Sudoku.

I wonder how the analysis would work here - since the verticals form words as well I think you get a lot more information from each guess. Many players can now solve them consistently in 6 or 7 guesses.