BWS Puzzle 19: Midi Themeless #9 (diagonal symmetry)

Check it out, diagonal symmetry! I didn't start out with that idea for this puzzle, but I realized it would work well with a couple of the 10-letter seed entries. I like how everything turned out, with the confluence of intersecting 10s toward the bottom-right*, as well as the sprinkling of mathematics in the entries in the top-left*.

* I've realized recently that I really don't like the NESW convention for referring to grid sections. I  can understand why it's used, but I honestly struggle to remember which way is East and which is West, in a way that I very much don't with Left vs. Right. So, I plan on continuing to use top/bottom & left/right instead. Hope that's alright with y'all.

However, I'm unsure about one particular square in this grid. It could have been an S, pluralizing both of the entries crossing there, but I ended up making it a black square. This increased the black square count beyond what I was hoping for, but there were already a few -S plurals elsewhere in the grid, so... I wonder if this example might help me understand what people prefer in balancing those kinds of considerations. Are these things you notice while solving a puzzle? Or just afterwards? Or at all? What about while constructing? Feel free to add any comments you have about all this.

Enjoy the solve, and share if you do! Constructive feedback in the comments is always welcome.

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