would you consider implementing a tetromino bag like the one described here[1], I think is common among the most popular tetris implementations, it affects a lot the game strategy, I think would make it more enjoyable.
This WASM version is based on my native code implementation which implements something like this.
I believe I independently discovered this concept of a tetromino bag. I've been calling it "Gambler's Accurate Model of Reality" in a homage to Gambler's Fallacy.
[1]https://tetris.fandom.com/wiki/Random_Generator