Instead of sending over mouse position as two floats (8 bytes total), the game will send the aim angle represented as a short (0 to 65535, so it's fairly precise) and the selected item ID (up to 4 bytes total, 2 bytes if it's only one of the inputs).
The problem with IsKeyHit is that it checked when the player started a key press, when it should've been checking for the key being released.
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