It's not absolutely required, unless the reload value is calculated.

When you have a fixed value like that, you can be pretty sure the LowByte won't overflow before it loads the HighByte.

However, you'll need to load the LowByte first, if you're not turning the timer off. And you'll also need to subtract 7 from the number you have, which is adjusted for a reload that does turn the timer off.
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